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Gunboat 68

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7 hours ago, Veeger said:

a curious misalignment of upper and lower parts of the daggerboard,... he observed.

Yep, our model builder has taken some initiative with the board design! That mini-68 arrived here all banged up from the travel... we managed to repaint her in time for the boat show but the boards will have to be sorted later on. Fortunately tonight we're having a few drinks next to the real thing... 

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One does what one needs to when your time is 'out' and the show must go on.  But when you've spent the money for a nice little model like that and you're advertising a high shekel product, it makes one ask about what 'other' shortcuts will be taken.  It's the little things.  Might have been better to not show any of the below water appendages.  More forgivable I think.  That said.  Nice boat!  If I had a few spare $5 million laying about, I'd come take a look.

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14 hours ago, he b gb said:

Wow! ‘Z’ boards ;)

ZiPtIp NoOdLe boards by Doug Lord for Gunboat.  LOL :D

 

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As mentioned above, GB have been posting more or less monthly updates on the design and build of the 68.

The latest one is about the rig design and the options available for the buyer.  It's kind of interesting.

https://www.gunboat.com/rigging/

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Should be a pretty cool boat. Word is it's about 2 weeks behind schedule (which is truly amazing). Full credit to the build team. That puts her in the water next month or two. I'm looking forward to seeing her floating.

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I took a fishing charter out of Wanchese last week, chatted up the mate and a few other locals about the industry. They'd had family members working on the Gunboat operation there... 

The development of this next series is fascinating! 

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Just noticed the hulls of GB6802 don't feature the reverse bows, at least they don't seem to ( see at about 0:50 )

Any explanation? Have they already changed the molds?

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It looks like they just haven't stuck on the "sacrificial" bows yet and you are looking a the forward watertight bulkhead instead...

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58 minutes ago, Airwick said:

It looks like they just haven't stuck on the "sacrificial" bows yet and you are looking a the forward watertight bulkhead instead...

Indeed, my mistake. I initially thought they did that by laminating a partiton rather than add a segment

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You can't get that final bow shape out of a mold, so it has to be added after release.

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11 hours ago, longy said:

You can't get that final bow shape out of a mold, so it has to be added after release.

Umm, please explain? The molds split along the centerline so I don't really see how the bow shape makes much, if any difference? Tons of beachcat and monohulls built with reverse shear on the bow everyday...

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44 minutes ago, samc99us said:

Umm, please explain? The molds split along the centerline so I don't really see how the bow shape makes much, if any difference? Tons of beachcat and monohulls built with reverse shear on the bow everyday...

Happy to! Definitely prefer to build the bows in one go, but it becomes a little hard with certain other constraints/must-haves: 

  • The reverse bow means it becomes extremely tight in the bottom. You can glue the hullside on but then all the taping has to be done from the outside. I've done this before on a similar type of boat and it does work, just means you have a bit more fine tuning to do on the inside before gluing to ensure a really good blind glue joint. 
  • That being said, VPLP really wanted a proper crash bow, our detail is very similar to most of their offshore tri's: The hull skins all join together aft of the bow (what you see on 6802) and the bow, which is completely filled with core and has an area of solid Carbon/G10 in the very tip, is this glued on and taped around the outside into pre-made recesses to avoid the taping bumps. 
  • They go even further than that with their detailed skin join details. I can't give away too much but it is cleverly done so that the bow can be completely ripped off without the hull skins being compromised. This also means that if (when) someone crushes a bow we can send them a new one and any good boatbuilder can cut away the old one and attach the new one.
  • We did try to go one step further and actually built the bow molds off the same plug with alignment pins, which means you can just glue the bows on in the mold and everything is perfectly aligned without a lot of hours. Shoutout to "CbrosTheDude" who noticed 6802 does not have her bows attached and upon demold, 6801 did. In fact, when we checked the bow mold to the hull mold before starting 6802 we noticed that one of the flanges had warped a little because it didn't have the best reinforcement from the mold maker. We decided we will attach 6802 bows the oldschool way (no less quality, just more hours!) and then solidly fix that mold flange for the next boat OR make a jig for post-bonding. 

Just the usual little surprises in boatbuilding you need to keep a wary eye for and be reactive to. Cheers, G

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Greenflash,

  Thank you for the detailed explanation. I totally get why you would go this way, my point was that you can build it all in one shot contrary to longy's belief.

  Beautiful boat and I hope she meets the weight targets!!

 

 

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Yes, I missed seeing the split hull mold, was focusing on the boat hanging in mid air. But even with the split, if the bow sections of the mold curved around to make the full bow section, it would not release from the mold unless you could move that part of the mold inward. As molds want to be very rigid (see comments on warp) that would require another detachable part of mould.

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On 9/11/2018 at 6:54 PM, longy said:

Yes, I missed seeing the split hull mold, was focusing on the boat hanging in mid air. But even with the split, if the bow sections of the mold curved around to make the full bow section, it would not release from the mold unless you could move that part of the mold inward. As molds want to be very rigid (see comments on warp) that would require another detachable part of mould.

You're absolutely right, you need a V-type split around the fattest part of the mold. 

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Congrats to the team in France. The new Gunboat 68 looks amazing. 

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You've mentioned none of these have been sold in 2 years, so are the 3 (?) in production right now potentially the entire run?

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36 minutes ago, guysmiley said:

You've mentioned none of these have been sold in 2 years, so are the 3 (?) in production right now potentially the entire run?

As far as I know there are only two 68's sold...but they are going ahead with production on hull #3 despite. I'd assume they'd just infuse the hull and stop there (but my intel may be wrong). 

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To be clear...it's a fantastic design that looks like it's been wonderfully executed. I reckon it's the best boat design ever. I don't want to take anything away from the folks who designed and built it. I look forward to seeing it on the water soon. 

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2 hours ago, soma said:

To be clear...it's a fantastic design that looks like it's been wonderfully executed. I reckon it's the best boat design ever. I don't want to take anything away from the folks who designed and built it. I look forward to seeing it on the water soon. 

Sure looks nice.  The top down shot makes the hulls look really narrow (a complement from my perspective; not criticism).  Maybe just the angle or the paint job, or it widens further aft but if you know and can tell... what's the L to B ratio of the hulls and is it more racey than normal for GB?

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11 minutes ago, Wess said:

Sure looks nice.  The top down shot makes the hulls look really narrow (a complement from my perspective; not criticism).  Maybe just the angle or the paint job, or it widens further aft but if you know and can tell... what's the L to B ratio of the hulls and is it more racey than normal for GB?

Yeah, the VPLP hulls are narrower and the bridgedeck is shorter than a GB66. The bows are longer and the sterns are longer, too. Overall, the bows are proportionally longer and the mast is (relatively) further aft. I fought a lonely fight and persuaded the group to make the platform wider. I would've gone another 2' wider (or more) but I had to compromise with an increase of ~18" for BOA. The beam on CL was more than that as a result of the skinnier hulls  

One of the interesting debates that I didn't agree with at the time is the stern immersion. VPLP felt absolutely certain that less rocker and stern immersion was fast. I'll admit that my stern-in adversion is a result of seeing too many GBs built too heavily. VPLP's argument was that a hull form designed to be stern-out that's too heavy and stern-in IS slow, but a stern-in hull form is faster...if it's intentional. Seeing the stern-quarter view below I have to admit, that slight rocker looks fast! The CFD said it was fast, too. 

 

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That shot is my new desktop background... I'm looking forward to seeing it rigged and in the water.

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6 hours ago, soma said:

Yeah, the VPLP hulls are narrower and the bridgedeck is shorter than a GB66. The bows are longer and the sterns are longer, too. Overall, the bows are proportionally longer and the mast is (relatively) further aft. I fought a lonely fight and persuaded the group to make the platform wider. I would've gone another 2' wider (or more) but I had to compromise with an increase of ~18" for BOA. The beam on CL was more than that as a result of the skinnier hulls  

One of the interesting debates that I didn't agree with at the time is the stern immersion. VPLP felt absolutely certain that less rocker and stern immersion was fast. I'll admit that my stern-in adversion is a result of seeing too many GBs built too heavily. VPLP's argument was that a hull form designed to be stern-out that's too heavy and stern-in IS slow, but a stern-in hull form is faster...if it's intentional. Seeing the stern-quarter view below I have to admit, that slight rocker looks fast! The CFD said it was fast, too. 

 

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My understanding is that immersed sterns ARE faster above 10-12 knots boat speed, but draggier below that. (compared to sterns out of the water....)

Similarly, more rocker is slower, but allows the stern to squat a bit more, thus raising the bows at speed.  These long, extended bows already have enough buoyancy so that the 'squat' isn't needed.   As I have observed my own cruising cat(s), I've long felt that the greater rocker was definitely slower.  My current ride has wonderfully long bows (relatively) and their buoyancy is a joy to watch and experience.  All very 'plebeian' however, compared to this speedster....

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7 hours ago, soma said:

VPLP's argument was that a hull form designed to be stern-out that's too heavy and stern-in IS slow, but a stern-in hull form is faster...if it's intentional.

Yes, rocker is bad to go fast. Sucks the transom down, increasing drag, until you get planing speeds.

Immersed sterns at low speeds bad. (but it's not an absolute speed of "10-12 knots" because planing speeds depend on waterline length). i.e. an aircraft carrier doing 40 knots isn't planing because the waterline is so long. Well and because it's very heavy. 

Volvo 60/65/70 are a perfect example of this too. Immersed transoms are used because they spend most of the time sailing very fast. 

Generally you never see immersed transoms on sailboats unless they are very fast. This boat probably is fast enough that most of the time it's doing 10 knots+. There will be a light air penalty but slightly immersed like these won't be too bad. VPLP have optimized it for higher wind speeds/boat speed

Now if they could just take a page from John Shuttleworth and consider the aero drag of that front bridgedeck cabin with the enclosed side wings. Just a big drag bucket. Picture holding up a 4'x8' sheet of plywood and walking into a 20 knot wind...

But overall, a lovely looking boat. How rich do you have to be to get custom solar panel shapes fabricated for you?

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2 hours ago, Zonker said:

But overall, a lovely looking boat. How rich do you have to be to get custom solar panel shapes fabricated for you?

Rich enough to swing a G68 I imagine... doubt the PV is but a rounding error!  What's the damage for something like that ready to sail?  My wife wants something that doesn't heel.  :)

What a vessel!  Looking forward to seeing her under sail.  

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Damn...that is an impressive boat on every level. That bridge deck cabin looks pretty fair considering the volume.

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10 hours ago, Zonker said:

...

Now if they could just take a page from John Shuttleworth and consider the aero drag of that front bridgedeck cabin with the enclosed side wings. Just a big drag bucket. Picture holding up a 4'x8' sheet of plywood and walking into a 20 knot wind...

...

Twenty years ago Shuttleworth was talking about the importance of catamaran hull aerodynamics. His article Beyond the Tektron 50 seemed to me, a lay person, a very sensible discussion of this.

Fig2-T50-and-D50-hull.jpg

http://www.shuttleworthdesign.com/img/

 Ever since reading it I’ve been struck with how many catamaran designs seem to go out of their way to increase upwind drag. Zonker, I know you’ve commented on this before ...why do so many of your profession ignore this?

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18 hours ago, soma said:

Yeah, the VPLP hulls are narrower and the bridgedeck is shorter than a GB66. The bows are longer and the sterns are longer, too. Overall, the bows are proportionally longer and the mast is (relatively) further aft. I fought a lonely fight and persuaded the group to make the platform wider. I would've gone another 2' wider (or more) but I had to compromise with an increase of ~18" for BOA. The beam on CL was more than that as a result of the skinnier hulls  

One of the interesting debates that I didn't agree with at the time is the stern immersion. VPLP felt absolutely certain that less rocker and stern immersion was fast. I'll admit that my stern-in adversion is a result of seeing too many GBs built too heavily. VPLP's argument was that a hull form designed to be stern-out that's too heavy and stern-in IS slow, but a stern-in hull form is faster...if it's intentional. Seeing the stern-quarter view below I have to admit, that slight rocker looks fast! The CFD said it was fast, too. 

 

IMG_5819.JPG

sexy

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A CFD analysis of drag at specific flow rates is short sighted.  An overall race model analysis is needed to paint the full picture.  For example, if you look at the Caribbean 600 the race is often won or lost in the light (behind Guadeloupe).  When comparing immersed transom candidate hulls vs hulls with the transoms clear the % speed difference can be substantial in the light.  In 6 knots of breeze if an immersed transom boat is only traveling at 4.5 knots and transom clear boat is sailing at 5 knots then the % speed advantage is 5/4.5 = 111%   In contrast if a transom clear boat is traveling 15 knots in 15 knots of wind speed, then a transom immersed boat will need to be traveling at 16.65 knots to have the same 111% speed advantage.  The speed benefit from flattening the rocker is unlikely to be 1.65 knots in the 15 knot wind speed range.  Race model analysis of most major ocean races for these heavy cats (heavy when compared to VPLP's stable of thoroughbreds) tells a pretty convincing story of defending light air speed advantages.  The reality is even more compelling than the mathematical model.  Punching through light air ahead of your competition opens up the tactical chess board.  We have all seen races where the rich get richer.  This racing analysis translates into a heavy cat's cruising capability.  Speed advantages in the light mean that the boat is more likely to sail in light airs rather than motor.  Immersing the transoms of the Gunboat 68 was a mistake.         

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I'd say naval architects are well trained in determining water resistance and have a good understanding of it, but few designers really think about aero (America's Cup level do of course, and I know One2Three commercial NA's in Australia run CFD wind studies for fast ferries).

John had an illustration of wind hitting a cat bridgedeck at about 35 apparent wind angle with cross sections. i.e. cat sailing to windward. He shaped his cabins to allow wind to flow over and around the sides. 

I'm not as big a fan of rounding the hull deck joint so much. Makes it really hazardous at sea unless you have a big toerail and well inboard lifelines. Super easy to slip off. I'm looking at lot of Schionning designs that do that too.

Totally agree with Any Old Username about how to model races - but maybe the client said "optimize it for top speed please"?  I'd rather have a boat that can slip along in light winds too. Maybe it's designed for trade wind ocean crossings only :)

 

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26 minutes ago, Any Old Username said:

A CFD analysis of drag at specific flow rates is short sighted.  An overall race model analysis is needed to paint the full picture.  For example, if you look at the Caribbean 600 the race is often won or lost in the light (behind Guadeloupe).  When comparing immersed transom candidate hulls vs hulls with the transoms clear the % speed difference can be substantial in the light.  In 6 knots of breeze if an immersed transom boat is only traveling at 4.5 knots and transom clear boat is sailing at 5 knots then the % speed advantage is 5/4.5 = 111%   In contrast if a transom clear boat is traveling 15 knots in 15 knots of wind speed, then a transom immersed boat will need to be traveling at 16.65 knots to have the same 111% speed advantage.  The speed benefit from flattening the rocker is unlikely to be 1.65 knots in the 15 knot wind speed range.  Race model analysis of most major ocean races for these heavy cats (heavy when compared to VPLP's stable of thoroughbreds) tells a pretty convincing story of defending light air speed advantages.  The reality is even more compelling than the mathematical model.  Punching through light air ahead of your competition opens up the tactical chess board.  We have all seen races where the rich get richer.  This racing analysis translates into a heavy cat's cruising capability.  Speed advantages in the light mean that the boat is more likely to sail in light airs rather than motor.  Immersing the transoms of the Gunboat 68 was a mistake.         

Top speed sells boats.  Maybe not in this case...

I suspect people with $6mm boats use the engine when sailing at 4.5knots is the alternative.

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28 minutes ago, Zonker said:

I'd say naval architects are well trained in determining water resistance and have a good understanding of it, but few designers really think about aero (America's Cup level do of course, and I know One2Three commercial NA's in Australia run CFD wind studies for fast ferries).

John had an illustration of wind hitting a cat bridgedeck at about 35 apparent wind angle with cross sections. i.e. cat sailing to windward. He shaped his cabins to allow wind to flow over and around the sides. 

I'm not as big a fan of rounding the hull deck joint so much. Makes it really hazardous at sea unless you have a big toerail and well inboard lifelines. Super easy to slip off. I'm looking at lot of Schionning designs that do that too.

Totally agree with Any Old Username about how to model races - but maybe the client said "optimize it for top speed please"?  I'd rather have a boat that can slip along in light winds too. Maybe it's designed for trade wind ocean crossings only :)

 

I completely agree about the rounded hull deck joint (I got lazy and chose that image as I couldn’t find one of cabin...which I think I remember seeing but can’t find).

At one point I seriously considered Wildcat/Charter Cat/Jaguar 35/6 catamarans (Schionning I believe). It was the right size and price point with better than expected performance. A a few day seatrial led me to believe everything I put down would quickly end up overboard. At that time I kept loosing skin diving paraphernalia over the side – fortunately shallow enough to retrieve. If I’d gotten one I hesitate to think how many of my daughters’ iPhones would have gone over the side.

Shuttleworth makes the point that bad aerodynamics not only limit speed it reduces safety in marginal conditions where you reduce sail area relative to parasitic drag which ultimately limits your ability to make headway to weather.

I’m bothered by the design of so many cats where the bridge deck cabin looks more like a wind scoop designed to maximize drag rather than deflect over and around. So often the offending bits appear to be purely aesthetic.

The forward cockpit cats (especially leopard) seem particularly bad. This gunboat seems to have executed the forward cockpit with least negative impact on aerodynamics (probably what you’d expect with the designers involved). But I’m just an armchair observer.

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52 minutes ago, Zonker said:

I'd say naval architects are well trained in determining water resistance and have a good understanding of it, but few designers really think about aero (America's Cup level do of course, and I know One2Three commercial NA's in Australia run CFD wind studies for fast ferries).

John had an illustration of wind hitting a cat bridgedeck at about 35 apparent wind angle with cross sections. i.e. cat sailing to windward. He shaped his cabins to allow wind to flow over and around the sides. 

I'm not as big a fan of rounding the hull deck joint so much. Makes it really hazardous at sea unless you have a big toerail and well inboard lifelines. Super easy to slip off. I'm looking at lot of Schionning designs that do that too.

Totally agree with Any Old Username about how to model races - but maybe the client said "optimize it for top speed please"?  I'd rather have a boat that can slip along in light winds too. Maybe it's designed for trade wind ocean crossings only :)

 

Looking at the pics (especially the top view), I'm pretty confident that VPLP ran full CFD on the platform. Of course there are always going to be compromises on a cruising cat that needs volume in the bridge deck module and so forth, but as I noted above, it looks pretty damn good, especially when you factor in end-plating the mainsail.

I also think you are underestimating the value of the chamfered hull/deck joint - the bows are fully exposed to the free stream flow, and the reward for both reducing aero drag forward and redirecting flow both upward and around the bridge deck would be significant. Aerodynamics can be very counterintuitive, especially in complex geometries like a big cat, and it's important to visualize the system as a whole.

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I'd actually be somewhat surprised if they did full aero CFD. Styling considerations probably drove a lot of the shape of the bridgedeck cabin.

WAG of flow visualization with boat beating to windward:

- The sunken cockpit induces a lot of turbulence in the flow

- the relatively sharp roof/front window joint ain't great (maybe it's more rounded than I think)

- the flow across the front saloon windows is right into the counterflow of the flow that hits the port chamfered front window.

- the port chamfered window is at 90 deg to apparent wind

I think you pay a big aero penalty for the front cockpit. and the wing style buttress windows. You'd be better off to have a low drag cabin and just have the recessed cockpit in front of it

What's a better shape for windward sailing:

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gunboat plan.JPG

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^ Look at how the front cross beam has been contoured to form a deflection panel. Look at how the aft corner of the doghouse has been chamfered to reduce frontal area at any APW angle forward of the beam. Look at how the radius of the doghouse roof increases as you move aft. All of those things suggest serious consideration was given to aero, and besides, VPLP have very sophisticated CFD capability in house - why wouldn't they use it?

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6 hours ago, Zonker said:

I'd actually be somewhat surprised if they did full aero CFD. Styling considerations probably drove a lot of the shape of the bridgedeck cabin.

I'm not sure about that, it actually looks quite un-conventional and pretty slippery to me:

The windward window is facing right into the wind deflecting the flow over the cabin.
The whole cabin is tapering aft like a (granted, truncated) "teardrop", and the back corner of the hard top are chamfered to limit frontal area
It also looks like the area where the solar panels are is not flat so that would smooth the transition from the side to the top
The bows are low and the deck tapers off going forward of the beam so more of the flow goes above them
The flow looks good until it hits the leeward inside face of the window, however at that point it's gone past the mast and you will have the jib and mainsail generating some low pressure above that that should suck the flow upwards.

So yes, there will be a bit of a stagnation bubble in that forward cockpit area but I'm not sure it's that bad for the overall flow with a lot of it deflected upwards above it anyway. I would say looking at it that they worked pretty hard to minimize the overall drag within the constraints of having that forward cockpit. That cockpit is also pretty small relative to the scale of the boat so it's not going to be that bad anyway.

I definitely wouldn't assume they winged it... these guys do race boats all the time so they certainly are well versed in aero drag! 

Also, I'm pretty sure it will be faster upwind that the Outremer (although that's a sweet boat that mere mortals could almost hope to own someday!)

 

 

 

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21 hours ago, surfsailor said:

I also think you are underestimating the value of the chamfered hull/deck joint

they put up some new pics today - one shows the chamfer pretty well, on both the outside and inside of the hull

looks pretty good to me...

 

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OK - thanks for pointing out some of the aero stuff I missed, especially thinking about flow influenced by the sails above, and the deckhouse chamfer edge I didn't see.

I think, given the constraints of the forward cockpit (and those stupid buttress windows) they did a decent job.

Next time they should have a fabric roller cover for the cockpit so when you don't have somebody in the cockpit you seal it off. When you open the front door to get into the cockpit it automatically rolls up in 1 second !

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Their FB page has some updated pics. By all accounts seatrials are going well. The boat is still in La Grand Motte. Word around the campfire is they still intend to sail the boat to the Caribbean in time for Les Voiles de St. Barth's in April. That seems aggressive, especially considering that the world's largest multihull boat show is right in LGM in April. 

No interior shots yet, interestingly. Sailing and exterior shots look great so far though.

I read an interview with the Managing Partner where he said (in French) that they totally underestimated the complexity of building the boat. That doesn't surprise me...

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Why does that not surprise me.  Seems this market is full of booby traps :-)

She sure is pretty from the outside though.

PS  Congrats on yur exploits on Chim Chim and also on Fujin in St. Maarten.  Just got back from VI.   Resilient place!

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Wow what a lovefest. There must be lots of well heeled folks on SA who want to overspend on a boat and hire others to enjoy sailing and fixing it all over so they can drop in for a week here and there and have some hired guns buy them a trophy in a rigged regatta.  

Have some class and buy a J class or similar classic. 

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On 1/17/2019 at 8:03 PM, Zonker said:

...Now if they could just take a page from John Shuttleworth and consider the aero drag of that front bridgedeck cabin with the enclosed side wings. Just a big drag bucket. Picture holding up a 4'x8' sheet of plywood and walking into a 20 knot wind...

Re lovefest, let me have my obsessions. I've lusted after gunboats since first walking on Safari...

I have a totally unreasonable fear of heavy weather and getting caught in Force 10 conditions. I know if I had a GB 68 I'd have good weather services available, I'd plan passages with weather windows, I'd keep an eye on satellite GRIB files (at a bare minimum), and there's very little chance I'd ever have to worry about stressing myself or the boat with extreme breaking sea conditions. 

BUT, I still have this voice in the back of my head that worries about one breaking wave getting past the bow buoyancy. I and I'd worry about those large flat slabs of glass. *But I have to say, the rational part of me thinks you could almost take one of these head on into the surf at Pipeline and not get the front cockpit wet. Those bows would instantly lift you over most anything. BUT I still worry. A freak gale combined with some weird opposing current up around Scapa Flow, some life or death situation where you had to get out of an atoll lagoon into breaking seas, or even seeing a tsunami headed right for you. In the back of my mind I'd worry about all that vertically flat glass. I think I'd have to have something rigged where I could string together a few of my fenders and line / lash them up in front of the cockpit and mast to absorb the shock of the water. As I said, totally unreasonable fear. Poseidon simply scares me...  

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On 3/6/2019 at 1:38 PM, LMI said:

Wow what a lovefest. There must be lots of well heeled folks on SA who want to overspend on a boat and hire others to enjoy sailing and fixing it all over so they can drop in for a week here and there and have some hired guns buy them a trophy in a rigged regatta.  

Have some class and buy a J class or similar classic. 

when you're too timid or fat to pay to be carried up everest...

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Good to see the 68 is sailing almost daily now. I've only seen one AIS speed above 20 knots, but that's why you seatrial. 

Still no shots publicly available of the cabins but the salon and fore/aft cockpits look great. 

I'd imagine hull #2 is getting close to unveiling. 

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The cockpit steps look nice but I'd want a handhold before going down them in a seaway.

Toe kicks for winch foot buttons are a very nice touch. More boats should copy that idea to prevent accidental activation

Wonder what sort of LED nav lights they use at the bow? Must be very waterproof. We mounted ours  about amidships on sides of the hull and found they lasted longer that way.

What is with the sharp corners the interior designers keep putting on boats? Do they not understand people have hips and boats fucking move around. (I'm talking about chart table edge, galley counter).  Grrrr.

Saloon visibility seems .... adequate

 

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That salon pic is dreamy. I think I just need to go rob a bank.

I will say that all the furniture and table finishes are great, but I'm kind of assuming that it's standard practice for everything that would look great for a dinner party has covers for daily use, right?

The other interesting thing would be to see the mounting hardware for removing furniture for regattas.

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Soma, Is Condor going to a Jamaican owner? Looking at the flag on the AIS screen shot. M.

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21 minutes ago, Student_Driver said:

Soma, Is Condor going to a Jamaican owner? Looking at the flag on the AIS screen shot. M.

Nope. US of A. Jamaica is a popular flag state for boats nowadays (along with BVI, Marshall Islands, St. Vincent, etc).

It had been previously shown as British flagged, but it changed a couple of weeks ago. I don't know what's changed. The registry on the transom was shown as Falmouth.

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From their facebook:

"Bow cutting through the chop, skimming along at 20-23 knots boat speed. At this point, someone asked "who wants a coffee? Gotta love this boat." - William Jelbert Gunboat COO

53469128_10156993596958490_617624503988353932270_10156992981923490_4291614644528

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2 hours ago, Se7en_speed said:

From their facebook:

"Bow cutting through the chop, skimming along at 20-23 knots boat speed. At this point, someone asked "who wants a coffee? Gotta love this boat." - William Jelbert Gunboat COO

Is that a PJ reference? Tea at 20?

 

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3 minutes ago, Keith said:

nice cat, tacky add.

Man if you've got it, might as well flaunt it.  The few times I've been up in the teens the situation was a hell of a lot different than that.  Amazing.  

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12 hours ago, soma said:

Is that a PJ reference? Tea at 20?

 

Dude is wearing a white cotton bathrobe in the video. Weird.  

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Student-Driver, I don't think you're getting the humor. Yeah, 20 knots. In your bathrobe, with the elegant tea service not even chattering on the flat table. While wind powered. It's funny. Welcome to Gunboat.

Re the pics of the boat at speed, even if you forget the practical / ease-of-use arguments, that reefed main just bugs me (and how hard can you walk on the solar panels without damaging them?). Whenever I fantasized about owning one of these, I was always willing to pay the weight penalty for a roller furler boom. Peter Johnstone always hated that and strongly argued against that (I think sailors who are racers to the bone react against tech that makes the sailing easy enough for civilians to go fast). When the roller furler with the sensible furling drum in front of the mast (whose mount actually makes the mast stronger) offered a carbon boom option, I was all over it. I love the option to easily reef and tune the balance of the boat and reduce sail for when it's really blowing, but still, Gunboat is resistant to the idea.

I had an obvious insight the other day and that is that the resistance might because the GB forward cockpit isn't all that compatible with a boom vang or rod, both because it would be very much in the way of the crew and dangerous in the cockpit, and possibly because the base of the mast is so close to the boom on the GB design that there isn't any easy (or low enough) mounting point for the vang or rod. Where does the mast sit, actually? Is it on the deck, or does it drop down to the floor of the cockpit?

Regardless, I had always gotten the impression that the roller furler boom absolutely required the vang / rod. All my research confirmed that, even though I didn't understand why. I wrote it off as being so heavy that a topping lift or other lines wouldn't offer enough support or it would simply bang around in rough weather (but the extra mass would also be a stabilizing factor). But I had another look and contacted the front drum company recently, and got this response from a well-known West Coast rigger / dealer about doing it without the vang / rod:

Quote

...we can make it happen.



Currently working on same scene scenario on another boat.  Will use a fixed length strop in lieu of vang to get perfect furling angle established, and combined with the topping lift(s), will work fine.

The square top main will be designed with vertical batten up top, possibly with a pocket for 45+or minus batten to be installed for the longer voyages.

Let me know if I can help in any way.  Spent hours working with H2O Extreme on rigging in the past."

 

About the only thing I still don't have a good handle on is the weight penalty between a stock boom and the furling boom in carbon fiber. That would be good info. I think with a careful skipper on the mainsheet, preventers on the boom during extended reaches, and maybe even a tiny camera inside the furling drum to monitor furling procedures against jams, a full stayed sail that rolled up in the boom would be practical.  It works in my head, if no where else...

 

*Edit. Oh yeah, I also can't see why the rolling furler wouldn't work even better with a rotating mast option. Other than cost, what's the downside of a rotating mast? A little heavier? Anything else? I think the pickup in performance is non-trivial. Somewhere around 10-15%?

 

GB vang mount.jpeg

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16 minutes ago, dcnblues said:

Student-Driver, I don't think you're getting the humor. Yeah, 20 knots. In your bathrobe, with the elegant tea service not even chattering on the flat table. While wind powered. It's funny. Welcome to Gunboat.

Re the pics of the boat at speed, even if you forget the practical / ease-of-use arguments, that reefed main just bugs me (and how hard can you walk on the solar panels without damaging them?). Whenever I fantasized about owning one of these, I was always willing to pay the weight penalty for a roller furler boom. Peter Johnstone always hated that and strongly argued against that (I think sailors who are racers to the bone react against tech that makes the sailing easy enough for civilians to go fast). 

First off, you're right, that reefed main looks like ass. "Someone get on that coachroof with some gd sail ties! We have a helicopter out here taking photos!"

As for a roller reefing boom...if you don't care about performance why buy (or entertain the thought of buying) a Gunboat? There are plenty of brands that abandon any pretense of sailing efficiency in favor of ease of use or ergonomics or whatever. Buy a Sunreef. Buy a Lagoon. You can paint any boat metallic gray...

The fleet are sailing with big roaches, up to 50% of the foot length. Horizontal battens matter. Sail area matters. Weight matters. You'd give away maybe 20% performance? A pinhead main with a hollowed out leech and vertical battens is S-L-O-W. Dealing with a normal mainsail is easy. Don't add complexity to create a solution without a problem. 

As for a rotating mast, it's nowhere near 10-15% gain. There are lots of "conclusive" studies on performance gain from rotating masts, all with contradictory results. Someone summarized the debate best when they explained how multihull rating rules treat rotating masts. The area of the mast is basically counted as sail area. In that case, it's about 10% extra sail area, but you don't get 10% performance gain from adding 10% sail area. 2%-3% maybe? That's probably generous. I think it's easier to just get extra sail area. But that's just my opinion and... 

"Opinions are cheap. Everyone has one".  

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40 minutes ago, soma said:

First off, you're right, that reefed main looks like ass. "Someone get on that coachroof with some gd sail ties! We have a helicopter out here taking photos!"

As for a roller reefing boom...if you don't care about performance why buy (or entertain the thought of buying) a Gunboat? There are plenty of brands that abandon any pretense of sailing efficiency in favor of ease of use or ergonomics or whatever. Buy a Sunreef. Buy a Lagoon. You can paint any boat metallic gray...

The fleet are sailing with big roaches, up to 50% of the foot length. Horizontal battens matter. Sail area matters. Weight matters. You'd give away maybe 20% performance? A pinhead main with a hollowed out leech and vertical battens is S-L-O-W. Dealing with a normal mainsail is easy. Don't add complexity to create a solution without a problem. 

As for a rotating mast, it's nowhere near 10-15% gain. There are lots of "conclusive" studies on performance gain from rotating masts, all with contradictory results. Someone summarized the debate best when they explained how multihull rating rules treat rotating masts. The area of the mast is basically counted as sail area. In that case, it's about 10% extra sail area, but you don't get 10% performance gain from adding 10% sail area. 2%-3% maybe? That's probably generous. I think it's easier to just get extra sail area. But that's just my opinion and... 

"Opinions are cheap. Everyone has one".  

He is talking about in-boom furling - NOT in-mast furling - very different animal and much less penalty in terms of sail design - can still do squaretop  main and horizontal battens

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23 minutes ago, Christian said:

He is talking about in-boom furling - NOT in-mast furling - very different animal and much less penalty in terms of sail design - can still do squaretop  main and horizontal battens

Yeah, I got that. It's a mess on a boat like this. 

Edit: yeah, I'm an idiot. Horizontal battens with roller reefing. But still a mess. 

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12 hours ago, soma said:

Yeah, I got that. It's a mess on a boat like this. 

Edit: yeah, I'm an idiot. Horizontal battens with roller reefing. But still a mess. 

I recently was looking at and talking to the owner of a Balance 52 which had inboom furling.  By the way not a bad looking boat.  He was the 2nd owner and said he was getting used to the system and making it work.  He said is would not have been his first choice but that is what the boat came with.  Two separate topping lifts to hold the boom up depending on what tack you were on.  Again he said it worked but would have much rather had slab reefing.  Just tricky without a rigid vang.  (He did not mention a temporary strop.)

There are lots of in boom systems installed and they must be working but for me just another system.  Also when it blows up at night there is nothing easier than just lowering the sail to a set mark pulling in the clew to its lock and attaching the new tack.   

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16 hours ago, soma said:

As for a rotating mast, it's nowhere near 10-15% gain. There are lots of "conclusive" studies on performance gain from rotating masts, all with contradictory results. Someone summarized the debate best when they explained how multihull rating rules treat rotating masts. The area of the mast is basically counted as sail area. In that case, it's about 10% extra sail area, but you don't get 10% performance gain from adding 10% sail area. 2%-3% maybe? That's probably generous. I think it's easier to just get extra sail area. But that's just my opinion and... 

FWIW - in the Mocra rating/formula for a Gunboat 62 (Elvis), the rotating mast gives about 3% more rated sail area and about a 1.1% improvement in the rating......

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20 hours ago, soma said:

...if you don't care about performance why buy (or entertain the thought of buying) a Gunboat? There are plenty of brands that abandon any pretense of sailing efficiency in favor of ease of use or ergonomics or whatever. Buy a Sunreef. Buy a Lagoon. You can paint any boat metallic gray...

Are you kidding me? Aesthetics and style are enough to buy a boat, even putting performance aside. Gunboats are GORGEOUS. AND,  they're the perfect execution of the new material making for lighter hulls. You don't see that all that often. Peter Johnstone was a genius in that. I think carbon fiber comes out of the spinning reel wanting to become a Gunboat. And by the way, racer types who don't do much but crew (and push) rich people's fast boats in regattas are free to have their preferences, but big cats are designed to be lived on. You got a problem with someone wanting a gorgeous and fast house, then you got a problem with me. "Half the reason to own a boat is just to look at it" -Francis Herreshoff. And who says you're giving up performance? You're paying a weight penalty (and I'm still trying to find out the rough percentage of additional weight), but you're not having to send crew aloft (or at least on their knees on your solar tiles) every time you want to reef or shake out the main, and maybe you've got minor additional drag due to larger boom, but it's a rounded boom, not a rectangle, so that's BETTER for performance, and in heavy wind with a reef you'd be a LOT smoother than tied-down flaked sails and you'd GAIN performance with reduced drag in high wind (drag being arguably the MOST important factor in any performance argument). Think about that when you're thinking of the Caribbean 600. You're confirming my theory about racers (no offense); I think you've got a grudge against 'ease of use or ergonomics or whatever.' Me, I'll take all the ease of use I can get. Sailing fast with a drink in my hand is a total win combo of nature, technology, and ergonomics. Johnstone sipping tee in a bathrobe indoors at 20 knots feels like a total victory in realizing the fantasies of every miserable sailor putting up with horrible discomfort in the history of sailing. But that's just my opinion.

20 hours ago, soma said:

...As for a rotating mast, it's nowhere near 10-15% gain. There are lots of "conclusive" studies on performance gain from rotating masts, all with contradictory results. Someone summarized the debate best when they explained how multihull rating rules treat rotating masts. The area of the mast is basically counted as sail area. In that case, it's about 10% extra sail area, but you don't get 10% performance gain from adding 10% sail area. 2%-3% maybe?

...Still a mess.

OMG you know so much more than me I don't understand how I'm ending up explaining to you, yet here we are. It's got almost NOTHING to do with 'sail area!' It's about drag, turbulence, and laminar flow. You REALLY wouldn't want to take a pair of regatta masts out of the gunboat factory and nail them onto the front of a 747's wings at an up angle of what, somewhere between 45 and 70 degrees? The burble of dead air killing the flow is the issue, and I GUARANTEE the 747 would have a greater than 3% penalty in lift (although of course this would vary with speed, but it's just a thought experiment anyway). Here, a better argument than I'm capable of: Rotating Mast argument (of a big Outremer cat, btw...).

Can you elaborate on why a neatly rolled sail is 'still a mess,' compared to manual reefing on the top of the roof, with tie down lines and loose sail all over the boom? And to forestall any argument about boom / mast angle, I don't get why this is any kind of issue at all. You watch the sail as it rolls into the boom. If it's coiling either aft or forward, you adjust the angle with the topping lift / strop. Easy peasy. I don't get the resistance to this.

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Maybe what we really need is a way to manage the reefed slab better. How about a wide, flat batten half way to the next reef that you can roll up the loose sail with? Might even do it from the mast and not have to go on the cabin top. 

Or, if with cars, the worlds shortest Dutchman on the leech with the slab reef clue line pulling on the leech in line with the cars?

Anybody try one of those?

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4 hours ago, Zero Gravitas said:

FWIW - in the Mocra rating/formula for a Gunboat 62 (Elvis), the rotating mast gives about 3% more rated sail area and about a 1.1% improvement in the rating...... 

I'm laughing out loud at this. Thank god the brilliant minds who come up with racing ratings don't design aircraft is all I can say. I think they'd be utterly baffled by the concept of flaps.

*Edit (and I'm imagining the Elvis crew laughing and high fiving each other when they got that rating).

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On 10/8/2016 at 2:49 PM, samc99us said:

Yes that's what he is referring to with end plate effect. I think it's a good idea, but there are some limits (removal of boom = lack of positive rotation in light air, but then you are motor sailing anyway?). It doesn't work if there is a gap between the sail and coach roof/trampoline etc. It needs to be as sealed as possible. The upside is a lower rig center of effort, no boom (thus lighter). Another downside is potentially less rig area up high and controlling the sail shape that low with such a large foot and no boom.

And, to go back to an earlier comment in this thread,  the rolling furler boom also has no gap between boom and foot of sail, so there's another performance  advantage we're not talking about (though I'd guess now we would only be talking about percentages under 5%). The conventional setup clearly doesn't have any means for "the prevention of lift-draining vortexes at the foot of the mainsail..."

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4 minutes ago, dcnblues said:

And, to go back to an earlier comment in this thread,  the rolling furler boom also has no gap between boom and foot of sail, so there's another performance  advantage we're not talking about (though I'd guess now we would only be talking about percentages under 5%). The conventional setup clearly doesn't have any means for "the prevention of lift-draining vortexes at the foot of the mainsail..."

Sounds like you have it figured out, DNC. I’ve got nothing to add. 

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19 minutes ago, soma said:

Sounds like you have it figured out, DNC. I’ve got nothing to add. 

To be clear, I'm very grateful for all your posts and knowledge. I think we differ in outlooks on how easy high performance sailing should be. I still have no idea how much heavier the carbon option from LeisurFurl would be, and that would be good to know. And I'm also confident that you've got an order of magnitude more knowledge and experience than do I. I'm perfectly willing to change my mind that, if money weren't a limitation, I'd rather have my main wrapped up in the boom and not flaked on top of it. I just need a better argument than the information I currently have. (Also to be clear, I wouldn't care at all about winning or even competing in regattas. I hope you can allow that some people would want the boat for all the sailing available that wasn't competitive. It does, after all, have four heads...)

*Edit I think another issue in this debate is a difference in perspective. You're thinking about max performance in ideal conditions and showing off the boat's design and paces that way. I'm thinking it's so damm high performance that as I'm moving my house from one anchorage to another in blue water swells, there's going to LOTS of times I'm going want / need to depower the vehicle. And a setup that makes that easier sounds very attractive to me.

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Beautiful boat. But I've gotta ask a couple of questions for an ad exec friend who knows nothing about enclosed cockpit catamaran sailing.

1 How's the guy in the bathrobe supposed to smell land or an incoming line squall over the aroma of the tea?

2 How does he see cloud patterns above and aft through that shiny roof?

3. How does he hear waves break on shore or on a reef? Or does the guy on the I Pad somehow have that triangulated?

4. Did they select a loose footed main so that if the guy in the bath robe has to reef all on his own in a hurry because his crew was too busy 'navigating' at the tea table...is the thinking that if he ran out of those pesky sail ties he'd have a spare in terry cloth?

This custom boat building stuff sure gets complicated in a hurry. 

 

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Fufkin,

     Your post reminds me of the delivery crew that flipped a Chris White Atlantic cat a while back just north of the DR while setting the table for dinner. Long thread here about that but I'm too lazy to look it up.

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Ras,

I didn't really check that thread, but followed the GB55 thread a little bit and the debate about 'sea sense' was a good one. I really dig the Gunboats, but if it were my money, I'd go a different  route entirely w outside steering.

Don't think I'll be forced into any hard decisions anytime soon!

 

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14 hours ago, dcnblues said:

 Here, a better argument than I'm capable of: Rotating Mast argument (of a big Outremer cat, btw...).

 

The explanation of aerodynamic lift in that link is so childlishly wrong that it negates the rest of the story. Still, a rotating rig has more power for the same sail area and is a bit more efficient. This is partly dependant on the relative area of the mast to the sail area, so it probably makes more sense on a beach cat than on a gunboat 68.

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2 hours ago, nyker said:

The explanation of aerodynamic lift in that link is so childlishly wrong that it negates the rest of the story. Still, a rotating rig has more power for the same sail area and is a bit more efficient. This is partly dependant on the relative area of the mast to the sail area, so it probably makes more sense on a beach cat than on a gunboat 68.

That article is painful to read. 

 

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    the article really strikes home when it claims you can just rotate the mast to unload the sail for reefing, without any change of course.

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On 3/17/2019 at 5:50 AM, dcnblues said:

I'm laughing out loud at this. Thank god the brilliant minds who come up with racing ratings don't design aircraft is all I can say. I think they'd be utterly baffled by the concept of flaps.

*Edit (and I'm imagining the Elvis crew laughing and high fiving each other when they got that rating).

Perhaps you should go for a sail on a large cruiser racer catamaran with a standard wing mast (That catana in the article would be perfect) Rotate the mast, un-rotate the mast while sailing and report back to us with the results.

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15 hours ago, nyker said:

The explanation of aerodynamic lift in that link is so childlishly wrong that it negates the rest of the story. Still, a rotating rig has more power for the same sail area and is a bit more efficient. This is partly dependant on the relative area of the mast to the sail area, so it probably makes more sense on a beach cat than on a gunboat 68.

Or an ORMA 60, IMOCA 60, or, wait for it, the regatta mast option on a Gunboat 68...

If the article is wrong about turbulence and drag, then what effect accounts for 'more power?' You're contradicting yourself by not giving more info.

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1 hour ago, bushsailor said:

Perhaps you should go for a sail on a large cruiser racer catamaran with a standard wing mast (That catana in the article would be perfect) Rotate the mast, un-rotate the mast while sailing and report back to us with the results.

You mean the Outremer 59 foot cat? The one with the rotating mast option? Like the Outremer / Gunboat 68 regatta rig option? Tell you what, I'm going to choose VPLP over your sarcasm.

Or are you straight-up accusing this guy (with no motive) of lying?

Quote

We were going upwind in a light breeze of about 7 knots just after completing a tack, with the rotating mast set straight on the center line of the boat. Once we had settled onto the new tack, we rotated the mast into the wind and I could literally feel the boat surge forward! Tests at different wind speeds and angles confirm that there is a 10-15% increase in performance with the mast rotated.

To be honest though, I want one as a fast and gorgeous liveaboard, and could not care less about being a knot or two faster or slower than another Gunboat. And I want as much ease of use as I can get. If a rotating mast makes the boom furling work better, then I'd spring for it in a boat I'm already spending 5 mil for...

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On 3/16/2019 at 2:56 PM, fufkin said:

Ras,

I didn't really check that thread, but followed the GB55 thread a little bit and the debate about 'sea sense' was a good one. I really dig the Gunboats, but if it were my money, I'd go a different  route entirely w outside steering.

Or, you could take two steps forward through the door on your right, or the door on your left to be outside (most likely with a hand on the wheel while doing so). If the roughly 2'x3' open window in front of you wasn't close enough to mother nature for you. Of course in heavier wind and swells, if you had boom furling and weren't in the middle of the Caribbean 600, you could easily reef down any percentage of sail you wanted, both to depower enough that you weren't worried about squalls / land gully gusts (which caught Fujin), to balance the steering, and to tune the boat to the rhythm of the swells. Easier on the boat, MUCH easier on the autopilot. 

But if you'd rather be out in the spray at the back of the boat with reduced visibility, pushing wind limits with your full main up and thinking about scrambling around on the roof with a handfull of sail ties (how would one rig a jackline on the roof anyway?), that's your choice. I love this design.

 

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Quote

We were going upwind in a light breeze of about 7 knots just after completing a tack, with the rotating mast set straight on the center line of the boat. Once we had settled onto the new tack, we rotated the mast into the wind and I could literally feel the boat surge forward! Tests at different wind speeds and angles confirm that there is a 10-15% increase in performance with the mast rotated.

I also think there be much more gain re/rotating option  from a production boat mast than a custom carbon racing mast. So the gain on a racer with an already optimised mast to reduce turbulence / cross section would be much less than a larger diameter stock mast.

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5 hours ago, dcnblues said:

how would one rig a jackline on the roof anyway?

Yellow webbing to the masthead?

Randii

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12 hours ago, dcnblues said:

Or an ORMA 60, IMOCA 60, or, wait for it, the regatta mast option on a Gunboat 68...

If the article is wrong about turbulence and drag, then what effect accounts for 'more power?' You're contradicting yourself by not giving more info.

Allright. If you want some more info, here you have it:

What's so childlishly wrong is this quote:

When the wind strikes the front edge of this rigid wing, the air is separated and must travel a longer distance in the case of particle A vs particle B. This creates a higher velocity on the top surface and a corresponding area of low pressure. So the wing is pulled upwards due to the lift force developed. This force is called aerodynamic lift.

Check this video for a simple explanation. The principle fault is the assumption that Particle A and B must meet again at the end. Also Bernoulli only accounts for flow without drag. So, in order to approximate the real world, you have to add a 'lift vortex' to get the correct flow over the wing. This also explains upflow in front of a wing/sail. And that's why you have to 'over rotate' a rotating mast.

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15 hours ago, dcnblues said:

Or, you could take two steps forward through the door on your right, or the door on your left to be outside (most likely with a hand on the wheel while doing so). If the roughly 2'x3' open window in front of you wasn't close enough to mother nature for you. Of course in heavier wind and swells, if you had boom furling and weren't in the middle of the Caribbean 600, you could easily reef down any percentage of sail you wanted, both to depower enough that you weren't worried about squalls / land gully gusts (which caught Fujin), to balance the steering, and to tune the boat to the rhythm of the swells. Easier on the boat, MUCH easier on the autopilot. 

But if you'd rather be out in the spray at the back of the boat with reduced visibility, pushing wind limits with your full main up and thinking about scrambling around on the roof with a handfull of sail ties (how would one rig a jackline on the roof anyway?), that's your choice. I love this design.

 

Any big cat is gonna have blinds spots. Over and above a good forward view and view of the leeward bow, to me, in a perfect daylit world, good visibility at the helm should hopefully include aft view, aft view up to clouds, a good view to windward and off your aft windward quarter(or windward hull in the case of a multi). IMHO the forward cockpits and forward steering stations on some of the Gunboat and Chris White designs might make this difficult. As for spray? 

In terms of efficient, fast mainsail reefing on a performance rig, shorthanded or otherwise, look to the Open 60s you mentioned as the gold standard. Full Battens, efficient ball bearing cars, and lazyjacks are, up to this point, hard to beat. Besides, it'll give the crew a reason to put their tea cups back on their saucers, drop the  IPad for a brief bit of digital detox and get outside to sea what's going on...

...but more importantly, what's with the notion that outdoor steering is such an uncivilized hardship?