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Actually, although it might not win, except in a drifter, a Dragon might be a decent trade off- if it rowed well. Do a turbo’d 2 head stay furling rig, couple of flying drifters, pretty low wetted surface at rest (and double ended at rest too, with a fairly low prismatic at low s/l ratios), they like ( and scoot) in a lumpy blow, protected cockpit, not too deep draft, good upwind, manouverable, a cabin ;).

Edit- of course they can take on water and sink, so you’d have to do something about that....:lol:... like flotation 

 

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I think you should be wary of comparing data like for like between monos and multihulls from different years. Saying monos have won almost half of the R2AKs has to do with who is signed up. The line u

All this talk about the best boat or best crew for the R2AK and I don’t see any mention of fully crewed monohulls. I find this interesting when, in fact, fully crewed monos have won the race two out o

Team Shunt Up and Drive?

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43 minutes ago, Amati said:

Actually, although it might not win, except in a drifter, a Dragon might be a decent trade off- if it rowed well. Do a turbo’d 2 head stay furling rig, couple of flying drifters, pretty low wetted surface at rest (and double ended at rest too, with a fairly low prismatic at low s/l ratios), they like ( and scoot) in a lumpy blow, protected cockpit, not too deep draft, good upwind, manouverable, a cabin ;).

Edit- of course they can take on water and sink, so you’d have to do something about that....:lol:... like flotation 

 

Sorry about the thread drift.... besides , a Udell or 22 or 30 sq m would be better...  

but back to muktihulls, would something like Sebago work? (A smaller one)

8CF0BD60-7210-4248-828D-1766DD2329A7.jpeg

AD9F8890-E993-4746-B5D2-2943BF538559.jpeg

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Not too far different from a Multi 23 which probably wouldn't be quite fast enough to win (probably) and would require lots of exposure but would be easy to propel and a pretty good all around design.  A couple mountaineering tents on the tramps would help as would being young and very tough.  

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33 minutes ago, Amati said:

Sorry about the thread drift.... besides , a Udell or 22 or 30 sq m would be better...  

but back to muktihulls, would something like Sebago work? (A smaller one)

8CF0BD60-7210-4248-828D-1766DD2329A7.jpeg

AD9F8890-E993-4746-B5D2-2943BF538559.jpeg

Calling Groucho Marx....Groucho Marx,  Groucho Marx....call for Groucho Marx

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32 minutes ago, mundt said:

Not too far different from a Multi 23 which probably wouldn't be quite fast enough to win (probably) and would require lots of exposure but would be easy to propel and a pretty good all around design.  A couple mountaineering tents on the tramps would help as would being young and very tough.  

Although I’ve doodled a longer middle hull....a longer carbon mast, multiple headstays,  the same foils...

:rolleyes:

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You could do that with the L7- keep the mast foot low so mast raising gets easy, boxes for the sliding beams on top of the middle hull, blister (use it as a mast crutch?) in back for helm protection.  Fold up the middle hull, tortured ply, simple shape, ~30’?  Whatever 1/4” ply might want to do for the displacement? 3/8’s?

 

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18 hours ago, Amati said:

You could do that with the L7- keep the mast foot low so mast raising gets easy, boxes for the sliding beams on top of the middle hull, blister (use it as a mast crutch?) in back for helm protection.  Fold up the middle hull, tortured ply, simple shape, ~30’?  Whatever 1/4” ply might want to do for the displacement? 3/8’s?

 

I was thinking about a 30' plywood tacking outrigger.  Maybe 700lbs lightship displacement with 200% buoyancy outrigger, equipped with water ballast and a 450 square foot square top main 130 square foot jib, 330 sq foot screecher, 450 sq foot drifter and 700 square foot asym. 

T foil for lifting the main hull, so it just kisses the water. 

I was thinking a plywood, but spaceship looking Va'a Motu... 

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7 hours ago, JanetC Gougeon32 said:

I was thinking about a 30' plywood tacking outrigger.  Maybe 700lbs lightship displacement with 200% buoyancy outrigger, equipped with water ballast and a 450 square foot square top main 130 square foot jib, 330 sq foot screecher, 450 sq foot drifter and 700 square foot asym. 

T foil for lifting the main hull, so it just kisses the water. 

I was thinking a plywood, but spaceship looking Va'a Motu... 

That is some boat.

An all carbon M32 light ship is 510 kg, with 53m2/ 82m2 SA and displacement Base Speeds of 13.5/15.7 knots respectively.

Your plywood tacking outrigger is light ship 320 kg, with 54m2/ 84m2 SA and displacement Base Speeds of 14.1/16.5 knots respectively. Base Speeds for both are with 3 crew weigh added and without the outrigger drifter and kite. T foils on main hull could also be interesting with the ama to leeward?

i have often thought that a proa with reversible T foil (near) bow rudders and a canting foil on the ama gives you a pretty stable 3 point lift. Use a beefed up version of this for foil control, because it is self contained and can reverse around with the rudders:

https://www.glidefree.com.au/

Coincidentally, my proa has reversible near bow rudders and a canting foil which lifts the ama at ~ 7.5 knots boat speed. I have many other things to sort out and play with first, but you never know.....

  

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There was a huge landslide in the Bute inlet. It created a massive wave of logs and debris that is going to be felt for a while. Good thing those logs disappear at night for you round-the-clock racer types.

 https://www.nationalobserver.com/2020/12/15/news/landslide-bute-inlet-wildlife-habitat-marine-traffic

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15 hours ago, Sidecar said:

That is some boat.

An all carbon M32 light ship is 510 kg, with 53m2/ 82m2 SA and displacement Base Speeds of 13.5/15.7 knots respectively.

Your plywood tacking outrigger is light ship 320 kg, with 54m2/ 84m2 SA and displacement Base Speeds of 14.1/16.5 knots respectively. Base Speeds for both are with 3 crew weigh added and without the outrigger drifter and kite. T foils on main hull could also be interesting with the ama to leeward?

i have often thought that a proa with reversible T foil (near) bow rudders and a canting foil on the ama gives you a pretty stable 3 point lift. Use a beefed up version of this for foil control, because it is self contained and can reverse around with the rudders:

https://www.glidefree.com.au/

Coincidentally, my proa has reversible near bow rudders and a canting foil which lifts the ama at ~ 7.5 knots boat speed. I have many other things to sort out and play with first, but you never know.....

  

I had Phil’s Foils make me an ogival foil designed by Tom Speer.  Found it on the web, and asked Tom for permission to use it, which he graciously gave.  He thought it would need a vertical trip (like fishing line)  to get best performance.  I didn’t get that far, but it seemed to work pretty well without one. I had it deployed as a windward board where I could see it easily, and didn’t see any ventilation, at any rate.

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23 hours ago, JanetC Gougeon32 said:

I was thinking about a 30' plywood tacking outrigger.  Maybe 700lbs lightship displacement with 200% buoyancy outrigger, equipped with water ballast and a 450 square foot square top main 130 square foot jib, 330 sq foot screecher, 450 sq foot drifter and 700 square foot asym. 

T foil for lifting the main hull, so it just kisses the water. 

I was thinking a plywood, but spaceship looking Va'a Motu... 

For what it’s worth, most of the locally made canoes up in that neck of the woods before Europeans arrived were flat bottomed.  The experimental ethno archeologist in my brain (the one on the hamster wheel) wants to believe there is a good reason for that- maybe better for running over all the junk in the water?  We had one sail from Sydney to Port Townsend about 10 years ago after a huge Hawaiian Express that was surreal- whole 80’ trees with root systems attached, along with square miles of smaller junk floating in the water- had to do the Shackleton lookout on the bow iceberg thing-  there was something every 20’ or so.  Gentle breeze at least, flat water, which made things easy.  All that just from stream runoff from rain, not a failing glacier.

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10 hours ago, Russell Brown said:

There was a huge landslide in the Bute inlet. It created a massive wave of logs and debris that is going to be felt for a while. Good thing those logs disappear at night for you round-the-clock racer types.

 https://www.nationalobserver.com/2020/12/15/news/landslide-bute-inlet-wildlife-habitat-marine-traffic

:huh:  Add to that micro quakes rearranging the coastline....  

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6 hours ago, Amati said:

For what it’s worth, most of the locally made canoes up in that neck of the woods before Europeans arrived were flat bottomed.  The experimental ethno archeologist in my brain (the one on the hamster wheel) wants to believe there is a good reason for that- maybe better for running over all the junk in the water?  We had one sail from Sydney to Port Townsend about 10 years ago after a huge Hawaiian Express that was surreal- whole 80’ trees with root systems attached, along with square miles of smaller junk floating in the water- had to do the Shackleton lookout on the bow iceberg thing-  there was something every 20’ or so.  Gentle breeze at least, flat water, which made things easy.  All that just from stream runoff from rain, not a failing glacier.

A Dory hull would be easier to build, and the weight penalty wouldn't be terrible. I was thinking the foils wouldn't go through through the because of the floating debris. Designing "innovative" and imaginary boats can be fun! 

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41 minutes ago, JanetC Gougeon32 said:

A Dory hull would be easier to build, and the weight penalty wouldn't be terrible. I was thinking the foils wouldn't go through through the because of the floating debris. Designing "innovative" and imaginary boats can be fun! 

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"Through through" is a technical term ;)

I meant to say through the hull.. 

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19 minutes ago, JanetC Gougeon32 said:

"Through through" is a technical term ;)

I meant to say through the hull.. 

Leeboards!  Or should I say surface piercing foils?  Anyway, I hear NACA 0012’s work pretty well- Moths were using them for the vertical foils in the beginning at least..

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Flat bottoms can be very fast as canoe hulls.  Many of the considerations for this type revolve around the materials used to build them.   One can make a good case for a lightweight glass ball hull as a structure but for pure speed flat wood is very hard to beat once it's on a plane.   My favorite shape/material blend is the triplane hull. which evolved into  the Greenough edge board bottom.  Most of the governing bodies out law concave hull forms, which also give great speed increases.   Freak freely.

 

 

 

 

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2 hours ago, Kenny Dumas said:

Flat bottom canoe better for taking ground/ dragging over mud and tree trunk rollers and skids??

Dory hull, with a Malcom Tennant looking old school bow. Leeboards and T foils hung from the Vakas - just a stupidly over canvassed, water tight canoe.  Even some of the old school Polynesian rigs tested very well in wind tunnels... and most of these rigs which are in use today literally use plastic tarps for sails and they are surprisingly fast. 

 

But a skinny concave hull is an interesting thought too.. The Greenough edge board idea for a canoe hull is fun to think about.  

 

 

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Janet, when I got out of college[pre-WEST]. I was commissioned to design endurance outboards by the man who held the patient for concave fluid lifting surfaces.   This was before the put the" pilots" in sealed fighter plane containers.   I drove for a while, and then turned that job over to people who had nothing to lose.  Our competition came from Italy[Molanari] their mahogany hulls were a modified split dory pickle fork type.  Ours were Eglass but the had concave longeron tunnels in the sponsons.   We didn't. have full sponsorship so we were giving them @20%  in HP but the lift and handling enable us to lap them after a couple of hours.   The next year concaves were outlawed.

 

 

 

 

 

 

 

 

o

 

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5 minutes ago, guerdon said:

Janet, when I got out of college[pre-WEST]. I was commissioned to design endurance outboards by the man who held the patient for concave fluid lifting surfaces.   This was before the put the" pilots" in sealed fighter plane containers.   I drove for a while, and then turned that job over to people who had nothing to lose.  Our competition came from Italy[Molanari] their mahogany hulls were a modified split dory pickle fork type.  Ours were Eglass but the had concave longeron tunnels in the sponsons.   We didn't. have full sponsorship so we were giving them @20%  in HP but the lift and handling enable us to lap them after a couple of hours.   The next year concaves were outlawed.

 

 

 

 

 

 

 

 

o

 

And this is the perfect race to play such a card... nothing has been outlawed yet

Bring on the concave skinny hulled tacking outrigger.  Dirt cheap rule beater.. 

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23 minutes ago, guerdon said:

Janet, Look up George Greenough, edge board.  That would be the call for seaworthy planing speed.

The early 70’s were such a deluge of ideas, and surfboard design was right in there.  Time to dig out the red and white T with the anthropomorphic fighter on it....

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1 hour ago, JanetC Gougeon32 said:

Dory hull, with a Malcom Tennant looking old school bow. Leeboards and T foils hung from the Vakas - just a stupidly over canvassed, water tight canoe.  Even some of the old school Polynesian rigs tested very well in wind tunnels... and most of these rigs which are in use today literally use plastic tarps for sails and they are surprisingly fast. 

 

But a skinny concave hull is an interesting thought too.. The Greenough edge board idea for a canoe hull is fun to think about.  

 

 

Thing is, flare is slow compared to vertical.  Harder to build too.  The idea behind concaves, in the windsurfing design scene, at least,  was to keep flow accelerating, to keep flow separation close to the hull surface.  I built my share.  But I gravitated to a smooth flat bottom with sharp chines and vertical sides.  There was a board shaper down in the Gorge (Hypertech?) who did the same with good race results- rocker became the holy grail, and outline.  But if you think about it, the low rider Skinny moths morphed into the same thing. Personally, I think both work, judging by the early pan am boards, and the speed needles.  It might be more a technical expression of sailing style.  If a smoother sailing style rewarded one bottom design more than the other, what do 2 parallel hulls and their rocker do to motion?  Or chop?

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1 hour ago, guerdon said:

Flat bottoms can be very fast as canoe hulls.  Many of the considerations for this type revolve around the materials used to build them.   One can make a good case for a lightweight glass ball hull as a structure but for pure speed flat wood is very hard to beat once it's on a plane.   My favorite shape/material blend is the triplane hull. which evolved into  the Greenough edge board bottom.  Most of the governing bodies out law concave hull forms, which also give great speed increases.   Freak freely.

Speaking of flats and concaves:

Rick Willoughby who has designed many HP “canoes” (with training wheels) uses flat bottoms exclusively. Some held endurance world records.
 
John Pizzey, eclectic proa enthusiast’s last “ideal hull” idea was a stepped flat hull form.
 
Take a look at the AC75 foilers, some with flats, some concave, anticipated benefits in air and water.
 
It is also a bit of “Back to the beginning” in that Commodore Ralf Monroe’s proas were all flat bottomed: http://www.thecheappages.com/proa/commodore.htm 3/4” bottom and 1/2” side planks. Some cross planking.
 
This thread drift is heartening because Sidecar has flat bottoms and flares, and where there aren’t flares, it is for a reason. Even 2 x  1/2” bottom and 1/2” side planks, with some cross planking.

 

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43 minutes ago, Amati said:

Thing is, flare is slow compared to vertical.  Harder to build too.  The idea behind concaves, in the windsurfing design scene, at least,  was to keep flow accelerating, to keep flow separation close to the hull surface.  I built my share.  But I gravitated to a smooth flat bottom with sharp chines and vertical sides.  There was a board shaper down in the Gorge (Hypertech?) who did the same with good race results- rocker became the holy grail, and outline.  But if you think about it, the low rider Skinny moths morphed into the same thing. Personally, I think both work, judging by the early pan am boards, and the speed needles.  It might be more a technical expression of sailing style.  If a smoother sailing style rewarded one bottom design more than the other, what do 2 parallel hulls and their rocker do to motion?  Or chop?

Good points! 

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36 minutes ago, JanetC Gougeon32 said:

This looks interesting, although it's a bit heavier than I was thinking - and the ama is a bit smaller than 200% buoyancy - but this is about what I was looking for, minus the plumb bow.. 

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I’m really digging the outline width forward on the outrigger hull coupled with the reverse shear and v’d bottom forward, which I bet winds up with a fairly normal displacement curve when pressed on starboard tack?  And a completely different (Prandtl?) main hull?  Pretty chunky prismatic there?

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1 hour ago, Sidecar said:

Speaking of flats and concaves:

Rick Willoughby who has designed many HP “canoes” (with training wheels) uses flat bottoms exclusively. Some held endurance world records.
 
John Pizzey, eclectic proa enthusiast’s last “ideal hull” idea was a stepped flat hull form.
 
Take a look at the AC75 foilers, some with flats, some concave, anticipated benefits in air and water.
 
It is also a bit of “Back to the beginning” in that Commodore Ralf Monroe’s proas were all flat bottomed: http://www.thecheappages.com/proa/commodore.htm 3/4” bottom and 1/2” side planks. Some cross planking.
 
This thread drift is heartening because Sidecar has flat bottoms and flares, and where there aren’t flares, it is for a reason. Even 2 x  1/2” bottom and 1/2” side planks, with some cross planking.

 

3DD7CBE1-0A69-49C9-A504-B2F5AA6E1FFF.jpeg

7DFD9846-9CDF-451C-AFBB-ABE30BF82608.jpeg

2806ED69-56FC-429E-878E-37592B1FE752.jpeg

Willoughby almost seems to be going towards streamlining, doesn’t he?  Very cool pressure recovery at the S/L ratios he’s shooting gor?

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Somewhere there is a video of pacific island model sail boat racing. No radio control, no rudders, all proas/outrigger canoes with a cloud of sail. Hull shapes are deep V for lateral resistance and directional stability, with a big flat each side to keep the hull up and planing.

This is all I could find:

https://www.bbc.com/news/av/world-25262184

And then there is Warwick Collins’ universal hull, and again a video of it sailing which I can’t find...

 

 

D4C448DC-7097-49F1-9C49-E788A5C32E7E.jpeg

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10 hours ago, Sidecar said:

Speaking of flats and concaves:

[...]
 
Take a look at the AC75 foilers, some with flats, some concave, anticipated benefits in air and water.

7DFD9846-9CDF-451C-AFBB-ABE30BF82608.jpeg

2806ED69-56FC-429E-878E-37592B1FE752.jpeg

How in the world is this ridiculous contraption, or tacking outriggers without safety amas, related to "R2AK best boat"?

 

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4 hours ago, ProaSailor said:

How in the world is this ridiculous contraption, or tacking outriggers without safety amas, related to "R2AK best boat"

Traditional SA thread drift.

With a bit of imagination, those foil arms could have safety amas on the end of them? As per Frog?

AC 75’s may capsize and are allegedly/potentially self righting, but at least they won’t flip like a multihull.

I personally think foiling offshore in log/debris strewn waters is mad on a kamikaze scale. But perhaps you have to be a little mad, like Randy Miller and Mad Dog to pull off the exceptional.

Imagine, you could do R2AK in just over half a day...... Speaking of flats.....

2739AE7D-CAB6-4C79-B9F4-D2CBBAB88CCA.jpeg

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1 hour ago, Sidecar said:

Imagine, you could do R2AK in just over half a day......

Your imagination is wilder than mine.  I was on San Francisco Bay in May, 2019, to see the SailGP catamarans doing ~50 knots on foils.  Extremely impressive for sure but limited to a narrow range of sea state and wind speed.  Way better than these silly AC75s but neither design is suited for Queen Charlotte Sound and Hecate Strait.  Bruce foils on low buoyancy amas are subject to complete loss of lift (righting moment) when the boat slows or stops suddenly, as it would when stuffed into a wave.  Old news.

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20 minutes ago, ProaSailor said:

Extremely impressive for sure but limited to a narrow range of sea state and wind speed....... neither design is suited for Queen Charlotte Sound and Hecate Strait.

Agree. Hence my fourth paragraph. And I wouldn’t regard an M32 cat as a suitable boat either.

FWIW, the AC 75’s have a Bruce Number of ~ 2.3, which is about as high as it gets, even with multihulls.

There are lots of ways to get to ~ 50 knots powered by wind, but the drag and cavitation involved getting there precludes going much faster.

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It seems like farmer logic [if a little is. good a lot is better].   Why zoom through a wonderful yet dangerous course?  I was always impressed by Russell Browns' ,  strategy of seamanship.  My son and I went to a futuristic amusement park with a new ride that was so scary the passengers didn't even scream.  Two days later. they closed it because two healthy people had died from pressure injuries to the brain.  30mph.through the water is equal to the speed of sound through the air.  Keep that in mind when doing endurance events that. affect your concentration/life.

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6 hours ago, ProaSailor said:

Your imagination is wilder than mine.  I was on San Francisco Bay in May, 2019, to see the SailGP catamarans doing ~50 knots on foils.  Extremely impressive for sure but limited to a narrow range of sea state and wind speed.  Way better than these silly AC75s but neither design is suited for Queen Charlotte Sound and Hecate Strait.  Bruce foils on low buoyancy amas are subject to complete loss of lift (righting moment) when the boat slows or stops suddenly, as it would when stuffed into a wave.  Old news.

Who said anything about a low volume float and a Bruce foil? 

 

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7 hours ago, JanetC Gougeon32 said:

Who said anything about a low volume float and a Bruce foil? 

I was responding to this:

15 hours ago, Sidecar said:

With a bit of imagination, those foil arms could have safety amas on the end of them? As per Frog?

I said "Bruce foil" because that's the context of my earliest memory of discussions about using foils for righting moment, but all foils need speed to generate lift (positive or negative).  If a boat is loaded up with sail and slows or stops unexpectedly, that foil lift goes away while the sail loads remain.  If the ama is low buoyancy (less than 100% displacement or zero on the AC75), over it goes.

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22 hours ago, Sidecar said:

Traditional SA thread drift.

With a bit of imagination, those foil arms could have safety amas on the end of them? As per Frog?

AC 75’s may capsize and are allegedly/potentially self righting, but at least they won’t flip like a multihull.

I personally think foiling offshore in log/debris strewn waters is mad on a kamikaze scale. But perhaps you have to be a little mad, like Randy Miller and Mad Dog to pull off the exceptional.

Imagine, you could do R2AK in just over half a day...... Speaking of flats.....

2739AE7D-CAB6-4C79-B9F4-D2CBBAB88CCA.jpeg

I think you might be able to argue that the AC underbodies can be thought of as amas, since they come into play in the same ways - out of the water at speed, safety for crashes and racing survival after falling off the foils, skimming the water at higher and lower wind speeds, and in Archimedes mode for low speed/at rest.  So from that point of view a look at very sophisticated and even better, varying shapes- no specific answer, which is excellent-

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In response to  Russ' post #310, a bit more from Rick Willoughby, posted last week on the Harryproa forum HarryProa@groups.io in response to a discussion on Shuttleworth style hulls.

"There are a lot of factors that make a pleasure boat useful.  Meaning it actually gives you pleasure rather than being a hole in the water that you pour money into.

As a concept, the Harryproa gives tremendous sailing performance for the money.  The length of the lee hull is likely the most significant performance factor overall.  Since sailing on the 18m/60' Harryproa I have watched quite a few faces light up once the awkward looking boat gets in its groove.  Sailors familiar with monohulls do not understand how a big boat with a small sail can take off and drive the way it does.  When in the boat yard for anti-fouling I have cause to compare the 18m proa with a myriad of cats and monohulls.  That comparison gives real insight.  There is an 18m long 0.6m wide knife sitting near hulls that I know from experience will be effective hobby horses.  There is nothing like rockerless length for slicing through the sea.
 
Any boat that operates outside fully sheltered water benefits from hull length.  The height of waves, given sufficient fetch, are simply related to the wind strength.  This is a useful calculator that matches my observations:
 
A 6m hull will be adversely impacted by waves in wind above 10kts and going will get tough by 15kts.  A hull needs to be up around 12m/40' to cope with the waves in 20kts of wind.  The 18m/60' Harryproa really gets challenging in 25kts but 15kts is delightful.
 
Frontal windage is a significant factor for windward performance.  Side windage can be a serious issue for confined manoeuvres.  Minimising exposed area and rounding corners certainly reduces side windage.
 
Generally the length of a Harryproa lee hull will be longer than the minimum drag hull for the same displacement and the design speed.  A realistic design speed is around windspeed or maybe 1.2X windspeed for a Harryproa.  There is no point having a design speed higher than the length of the hull permits for the waves it will encounter at that design speed.  So a 6m proa will not handle waves well in winds above 10kts.  So if it is designed to do 1X windspeed then the design speed will be around 10kts.  A 6m hull designed for that speed would have close to a rectangular immersed section.  Whether it is flared or not will not make much difference to calm water drag.
 
A Harryproa with 12m/40'  lee hull could have a design speed of 15kts.  
 
There is great merit in simplicity of build.  Unless you can go and step aboard a boat that you can afford and meets all important requirements, the best approach is to get started.  It is possible to go through endless design spirals and never build anything.  At some point you just have to go do it.  The sooner the boat gets wet, the sooner the big learning experiences.  The development that comes from those experiences, with thoughtful redesign will be the most valuable and exciting time of the project."
 
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due to a late change in my sailing plans... Buzz my Seacart 30 (probably the best of the best) will coming on the market very soon. Can fit into a shipping container, a definite RAK winner in right hands

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