hannibalhouse

What Ever Happened Truly SHALLOW draft cruising multihulls?

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Shallow draft used to be (ok, in the ‘70s) a given with cruising multihulls.  By shallow draft I mean a boards up draft of 2-3 feet was commonplace.

Today most large cats and trimarans come with minimum drafts in excess of 5-6 feet.

Designers should be advised that places like the Chesapeake Bay and the Gulf of Mexico and their adjacent inland bays and rivers have not been deepened.  There are many places 5-6 feet cannot go, whether gunkholing or marina hopping is your desire.  The Rapido and the Dragonfly trimarans are “shallow draft”.  The Neel is not (but could be with a lifting board(s) configuration).

Why have most (not all) catamarans abandoned shallow draft?  Thoughts?

 

 

 

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It is much cheaper to build fixed keels for the condo cats than daggerboards. Daggerboards take up space where you can fit an extra head. The market has spoken.

Unless you're talking about really large cats, they don't draw 6' though. Lagoon 620 = 5'-1".  Oh, you also need draft because they keep getting heavy. So the hull gets deeper and the keel gets deeper to keep span reasonable.

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The Cruising area available in the Bahamas gets killed by deep draft. Shallow draft opens up all kinds of inexpensive dockage opportunities which would otherwise make owning a multihull prohibitive.

My St Francis 44 draws 3' with low aspect keels which are frowned upon for upwind work. I installed 2" thick high density foam cored, bi-axial glass skinned, end plates which extend 2" horizontally outside the keel ends. They now work quite effectively beating to weather and provide an excellent grounding base and damage absorber.

Deep daggerboards and rudders are more efficient but at the expense of increased maintenance, cost and crash protection.

Check out the track on the windward leg on the Atlantic Highlands Fling posting this year - on the latter part were making 90 degrees, tacking through closer to 80 and gaining on a well sailed, centerboard equipped Dragonfly1000 (which can also operate in shoal water) - amazing!

You have a good point and production multihull builders shouldn't discount the possibilities.

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Whatever you choose to put below the waterline, boards or keels , the saildrives/props are going to draw close to 3 feet and you don't want those banging on the bottom.

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49 minutes ago, MRS OCTOPUS said:

Whatever you choose to put below the waterline, boards or keels , the saildrives/props are going to draw close to 3 feet and you don't want those banging on the bottom.

2'1" boards up draft and saildrive is not the lowest point with the boards up.

image.thumb.png.fa43fe5e35635cda3aae1505cc825fee.png

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2 hours ago, KC375 said:

2'1" boards up draft and saildrive is not the lowest point with the boards up.

image.thumb.png.fa43fe5e35635cda3aae1505cc825fee.png

Nice boat.

The downside , with the sail drives so far aft, is the weight is way aft and the   props suck air pitching into the short steep stuff.

Good luck opening the engine hatches in a following sea :) , I'm purely guessing on the  reason for the aft location is to isolate the smell from the accommodation and nothing to do with performance.

Everything is a compromise, including draft.

Google turns up... https://newboats.ru/view.php?boat=164216

Shows draft at 54 cm to 2.6 meters.

Less than 22 inches to 8'8".

Out of interest is this your boat  or is it it Russian internet vapourware?

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30 minutes ago, MRS OCTOPUS said:

Nice boat.

...

Out of interest is this your boat  or is it it Russian internet vapourware?

Seawind 1160

Seawind-1600-offshore-cruising-catamaran

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I would always choose the shallowest possible for cruising - Bahamas, beaching  etc.   Some compromise as there is some more work to do in build.   We have used single central board and single lifting rudder and v. happy with the result, particularly when including a trim board in one or both transoms.  STEERING is simpler.  We have always offered some form of lifting boards and rudders for DIY clients.   Cool Change  Happy boating has boards, lifting rudders and props retract into the hulls.   Happy Boating, Derek

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1 hour ago, Derekkelsall said:

I would always choose the shallowest possible for cruising - Bahamas, beaching  etc.   Some compromise as there is some more work to do in build.   We have used single central board and single lifting rudder and v. happy with the result, particularly when including a trim board in one or both transoms.  STEERING is simpler.  We have always offered some form of lifting boards and rudders for DIY clients.   Cool Change  Happy boating has boards, lifting rudders and props retract into the hulls.   Happy Boating, Derek

Main problem with a central daggerboard and central rudder is the amount of sea grass etc that collects on them and the need to constantly lift them to clear the debris. I 

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Yeah, well, fixed mini-keels vs daggerboards.  The DIFFERENCE is in windward performance.  Effectively, maintenance is no more difficult with daggerboards than mini-keels.  Sure, I pull them out to paint and inspect during haul out,(or find a place that can handle their beam) it's not a big deal anymore.  Yeah, you might have to replace or screw around with a control line sheave in an awkward place.  It's all easier than changing the oil on your diesel.

Beaching!  Ha!  That was important 50 plus years ago when the cheap homesteader types couldn't afford a haul out.  If you've got a production cat, you can afford a haul out periodically.  So after I've hauled and painted my boat, tell me again why I want to 'sand' it all off on a beach?  btw, with daggerboards and lifting rudders, the whole hull will be on the beach, how ya gonna paint THAT?  Minikeels at least minimize the places you can't paint and they protect your sail drives (which would be jammed in the mud on a truly shallow hull.  Even with mini keels, the what other boat type has less than 5'-6' draft? (that's 40, 50+ feet long?)

You also can't SAIL in shallow water with a daggerboard fully retracted.  So the advantage is what? that you can motor into some shallow, bug infested swamp?

There's too many other things that are much more important when selecting a boat.  Ya want shallow draft?  Find a 28' centerboarder or something.... 

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8 hours ago, nroose said:

Looks like a photo of a 1600.

Correct, I mistyped.

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Created a 55' cat a number of years ago that can motor in 30" 'of water.  The boat has daggerboards and rudders in cassets, so the foils can be fully retracted. (Fully deployed, the boards draw 10' and the rudders about 4'.)  Took the sail drives off the backs of the engines and rotated them 45 degrees inboard, so they came out the inboard sides of the hulls, with the hubs just above the plane of the keel lines.  so, even if the boat dried out, there was no damage to them.  I was initially concerned about cavitation, but the motors were far enough forward (for weight distribution) that cavitation was never a problem.  

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13 minutes ago, pwormwood said:

Created a 55' cat a number of years ago that can motor in 30" 'of water.  The boat has daggerboards and rudders in cassets, so the foils can be fully retracted. (Fully deployed, the boards draw 10' and the rudders about 4'.)  Took the sail drives off the backs of the engines and rotated them 45 degrees inboard, so they came out the inboard sides of the hulls, with the hubs just above the plane of the keel lines.  so, even if the boat dried out, there was no damage to them.  I was initially concerned about cavitation, but the motors were far enough forward (for weight distribution) that cavitation was never a problem.  

...and both Indigo and Merlin are the best examples of beautiful multihull design ever done in both large and small cats!

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The sail drives in my St Francis are mounted the same way and never had any cavitation issues.

Low aspect keels and fixed spade rudders allow the boat to dry out and protect the sail drives, plus I get low set, chilled water tanks and bilge/grey water sumps. Pretty routine for scrub and maintenance drying and no rocks punching dents/holes in the hulls.

Can well afford yards but hate hauling there and secluded beaches are way more enjoyable.

Years ago I was pitched selling the St Francis and Skateaway and buying the 55' Wormwood (Avalon?) on the basis she would deliver the best of both worlds - stepped away as just too much boat for me to handle and maintain - never regretted that decision - personal of course.

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2 hours ago, Veeger said:

...and both Indigo and Merlin are the best examples of beautiful multihull design ever done in both large and small cats!

Merlin and Indigo from other SA threads

image.jpeg

IMG_3359s.jpg

image.png.78b747b0cd77d54d8e736580afcb18b0.png

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Bow shackle and stainless open thimble on the seagull striker cable! WOW.

Sure is a beautiful cat though.

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I only beached my cat to paint the hulls once. Used two big truck tires under the hulls so we did paint the bottom effectively. No worse than lifting straps or keel blocks.

Except these tires floated so hard to keep them in place as the boat settled.

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5 hours ago, PIL66 - XL2 said:

Anymore info on the bottom cat.... 

I think there are others on this site ( @pwormwood ) the designer, who know more than I but I'll share what I have

INDIGO FLYER - 71’ WORMWOOD DOUGLAS BROOKS 1989 strip planked red cedar (also described as 67')

Peter's comments from Stiletto site:

When I designed Indigo the rig was considered so radical that I agreed to skipper her for awhile just to make sure that I hadn’t created a monster. At the time, cruising cats had big genoas and small mainsails. The thing about big genoas is that they really load everything up – including the sheet winches. Prior to starting the boat, the client chartered another 67′ cat so we could get a feel for that size boat. We were sailing it in Antigua race week. The owner of the boat brought a body builder aboard to crank the winches. After noticing that all of the bronze winch handles were bent over from this guy cranking, I realized that normal sized people, using the largest winches available at the time, were not going to be able to get the job done. In addition, a genoa of that size is not something a cruising crew could easily lug around the deck, hoist, etc. I had just come from 2 years of racing Formula 40’s in Europe, and with Prosail in the US. Because of their big mains and little jibs, a 40 could be sailed by two people, if you didn’t put the spinnaker up. So, with that piece of information, I put the first modern rig on a cruising multihull. Since a major part of the sail area went into the main, the mast was humongus, compared to other cruising cats. They thought I was crazy…so I agreed to skipper the boat. As it turned out, two people could sail Indigo – from anchor up to anchor down. Now, all you see are cruising cats with big mains and small jibs. So, there’s a little piece of history that I bet none of you knew…

And, as a bonus, here’s another – after designing the sail plan, I realized that, as big as the main was, we had to make it easy to get up and down. So, we decided to use a 2:1 halyard, and a Harken track for the luff system. This was back before Harken really offered a ‘Bat-car system’. Using their existing track cars, I calculated that, when the mainsail was down, the stack of cars would be 12′ high! OK – try putting a mainsail cover on that!! So, I contacted Harken and asked about the possibility of making really short cars (around 3″) for the slides between battens, and only slightly longer ones to receive the battens. Well, it worked so well that you can now open a Harken catalog and find several sizes of luff systems that all have their genesis aboard a catamaran named Indigo.

Photos mostly @brian eiland

34380-1f3b0c63777c0c3d2579754eceffb832.j  34381-cb1138e7df929814426dc027948bacba.j  34382-3a8818ad98384196a15d024b28845c5d.j  34383-ae3dc276bffd9b90d013a3c756f9869c.j 34384-61ffcdbb5084e9305571427a75ea8fbc.j  34385-d5a3ab047f1c2d6b5868d5fc7861b70a.j  34386-4e235ef933ee303865d333237c853ad0.j  34387-d549e8011cc9f6eefcb677285e024551.j

A bit of history on boat can be found here (pdf)

 

 

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6 hours ago, Zonker said:

I only beached my cat to paint the hulls once. Used two big truck tires under the hulls so we did paint the bottom effectively. No worse than lifting straps or keel blocks.

Except these tires floated so hard to keep them in place as the boat settled.

I bottom painted the proa many times between tides. One time I did it on a sandbar in a very lonely place in New Zealand. I blocked the boat up as the tide was going down but still had to shovel a trench under the keel. It kept filling up with water so I was madly pumping the water out of the trench so I could flush with fresh water and paint, but it kept filling up and I kept pumping with my head under the boat and then I got the feeling I was being watched..... I turned around and there was a whole herd of cows right behind me in a row with their heads down. I yelled and jumped up. They took off, wildly kicking their heels. end of story.

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14 hours ago, Zonker said:

I only beached my cat to paint the hulls once. Used two big truck tires under the hulls so we did paint the bottom effectively. No worse than lifting straps or keel blocks.

Except these tires floated so hard to keep them in place as the boat settled.

Sand bags work pretty good. Anti fouling between tides is just one of many benefits of keeping draft as shallow as possible.

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8 hours ago, Max Rockatansky said:

1992 Catana, spade rudders 2.5’, saildrives shallower. Boat can be beached. Pic not my boat

4AAC6841-011F-4517-B380-BE2F272F82A2.png

 

19 hours ago, PIL66 - XL2 said:

I got a survey done on the beach

Tennant 52 .jpg

Great illustrations of the agony and the ecstasy of a beachable cat!  Paint the bottom? Hah, not me, thanks anyway.  Inspect? Clean the topsides?  Sure, sweet, provided that it's hard sand, no wakes/waves and especially no MUD!  Sandbags have been used successfully in a number of instances, fussy though to make it all land just right and requires some pre-planning/locating of said sand bags.

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I had seen threads on Indigo before, but I never connected it to the write up on the Stiletto website... damn what a boat!

That Tennant Pil beached looked cool in Yachtworld... how did she look up close?

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2 minutes ago, Geese said:

I had seen threads on Indigo before, but I never connected it to the write up on the Stiletto website... damn what a boat!

That Tennant Pil beached looked cool in Yachtworld... how did she look up close?

Very big.... I still wish I had bought it but sailing home across the Tasman Sea was risky and i hear the people that bought it in the end had rudder failure so might have dodge a bullet...

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When Afterburner went for sale in the 30k$ range I did some serious soul searching, I can’t handle that boat... will I have the skills/means before I’m physically not able?...  gotta raise my little baby daughter and then seek to answer a question like that.

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4 hours ago, Geese said:

When Afterburner went for sale in the 30k$ range I did some serious soul searching, I can’t handle that boat... will I have the skills/means before I’m physically not able?...  gotta raise my little baby daughter and then seek to answer a question like that.

The answer is .... if you can afford to run a boat like afterburner then absolutely buy it... I went down the same path and i don't regret it... At 53 it's getting harder physically so i said I'm not going to die wondering and bought XL2

I'll discussed buying Afterburner but it is a one trick pony and the logistics of getting it to oz messed with my head .....

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When planning a careening scout the beach the previous low tide for big rocks, logs etc. Place one or two vertical sticks in the water to live near up boat centreline so you know exactly where your landing zone will be.

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6 hours ago, Zonker said:

When planning a careening...

Interesting. Is it still 'careening' with a catamaran sitting level? Semantics, I guess... 

Webster sez:

1 : to put (a ship or boat) on a beach especially in order to clean, caulk, or repair the hull
2 : to cause to heel over

I guess I have careened my beachcat to retrieve a halyard... :p

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On 12/15/2019 at 4:22 AM, hannibalhouse said:

Shallow draft used to be (ok, in the ‘70s) a given with cruising multihulls.  By shallow draft I mean a boards up draft of 2-3 feet was commonplace.

Today most large cats and trimarans come with minimum drafts in excess of 5-6 feet.

Designers should be advised that places like the Chesapeake Bay and the Gulf of Mexico and their adjacent inland bays and rivers have not been deepened.  There are many places 5-6 feet cannot go, whether gunkholing or marina hopping is your desire.  The Rapido and the Dragonfly trimarans are “shallow draft”.  The Neel is not (but could be with a lifting board(s) configuration).

Why have most (not all) catamarans abandoned shallow draft?  Thoughts?

 

 

 

Plenty of good boats out there  with shallow draft, mostly custom builds, but some production, eg Seawind 1190 Sport

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Just yesterday I rode my bike, after four years, toCaboolture train station , then from Ferny Grove (furry groove according to some young bucks) to Dayboro. Im sixty seven and intend continuing to learn sailing again after a rehab break of four years. This world we live in cant stop or we all lose. Buy the boat ,listen to PIL-XL2 Cheers ,Peace to allmen , and especially women, the kind ones that is,, Bottman

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Seems that performance catamarans with daggerboards had much shallower drafts than those without daggerboards. 3 feet for the Outremer 50 light http://www.sailtahiti.com/en/portfolio-items/outremer-50-light-2002/ versus 5 feet for the Crowther http://www.sailtahiti.com/en/portfolio-items/crowther-nordest-63-1996/?portfolioCats=222

 

 

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17 hours ago, Sail Tahiti said:

Seems that performance catamarans with daggerboards had much shallower drafts than those without daggerboards. 3 feet for the Outremer 50 light http://www.sailtahiti.com/en/portfolio-items/outremer-50-light-2002/ versus 5 feet for the Crowther http://www.sailtahiti.com/en/portfolio-items/crowther-nordest-63-1996/?portfolioCats=222

 

 

DID YOU BUY AN AD?

As much aus I like the Outremers, they are a bad example of a shallow draft multihull because of the fixed rudders. 

Paul

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