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It could work for R2AK but an 18’ long version might be better for accommodating 2 people.

@@AaronNunn-y5m thanks. I think if I had a larger sail I could get 15 knots out of my 14’ prototype and maybe 16-17 knots out of the larger version.

I think the wing stubs and folding winglets look much better than the crossbar. The cool thing about this design is that 1 person can walk onto the windward wing and hold on to the strut. This provides even more righting moment. I did this on my Dad's wingmaran once.

The center of effort always acts on a diagonal line across the boat. So when you move the sail towards the windward hull, as I have done, it must also move backwards, otherwise it is no longer on the diagonal line. People get confused when they break the sail's force into heeling and pitching. Both happen at the same time, that is why the CE is a diagonal line. It acts perpendicular to your sail and through the center of lateral resistance. So that is why Atlantic proas have their sails farther to the back. But the correct place for a Pacific proa sail is closer to the front. Think of a person being pulled by a kite. If the kite string was not in front of them, there would be no forward force, so the kite sail is also both in front of the direction and downwind of the direction (diagonal line) and the force of the kite sail goes through the kite string. It is no different with a conventional sail going perpendicular to the boom.

@@markgallagher1376 because the hulls are both skinny they will sink about 5”. The sharp chine should provide enough leeward resistance but I could always add a leeboards if needed.

​@@markpalmquistwhat hull ratio are the hulls?

@@dominictarrsailing currently the hulls are 12 to 1 fineness. and the main is exactly twice the length of the leeward float which only has to keep the hydroplanes above the water until the boat hits about 7 knots, then the dynamic lift takes over.

I agree, more mast tilt and a taller mast to hold the yard higher, and push the sail forward. Yet very cool! Keep Shunting, Balkan Shipyards

I agree, currently it looks like it would turn into the wind a bit but there are a few ways to correct this. 1 is to loosen the back stay so the offset mast leans forward more, or, you could increase aspect ratio of the sail and shorten the boom, or you could make the Lee float asymmetric.

@@markpalmquist Big rudders, hull asymmetry are solutions, yet they increase turbulence and drag. On the other hand moving CE is truly the best way. If not possible, appendages, or hull shape can move CLR, understood. The question is, can you move your luff ahead and still shunt, or will it bump into the mast? Otherwise, how much are you willing to move the sail towards the Ama?? I like it, I just know how annoying excessive weather helm is, and how small hulls battle in light winds, the ugly ripples appendages add... Good Luck Mark, love your style! Keep Shunting mate Balkan Shipyards

@@BalkanShipyards thanks! I have learned a lot from watching your videos and also Vlad. I agree the best way to maintain helm balance is with sail's placement. Because I need distance between the sail and the skimming outrigger I have moved the sail more central which also allows me to move it slightly backwards because the CE moves along a diagonal line. but I agree it still appears to be behind the center of the hull's lateral resistance. I think making the smaller ama asymmetric in this case will be fine because it has a slightly higher aspect ratio than a longer hull would have, so it might be more efficient at turning fluid downwind and helping to resist leeway. But I am not sure. The ideal situation is no rudders at all but leaning sail forward or aft for directional control but that might be tricky. I might need 2 winches, 1 on each side.

@@markpalmquist I hope it works Mark, Good Luck! If leaning the sail is achieved by canting the mast, probably a block and tackle would be enough, could be easily done with double or triple blocks with a cam cleat, you would probably need much less than half a meter of block and tackle at the bottom end of the backstay...

I will try that. The only issue with that is in low winds the back of the boom will swing towards me. I could have the cant adjustable depending on wind strength.

This is just under 16' long and the main hull is just wide enough to get both feet on the floor. The deck overhangs the sides to create a place to side. Shunting requires that you jump through the A frame to get to the other side of the boat. Bow becomes stern, stern becomes bow. The boat is symmetric about the central cross plank.

​@@markpalmquist since the sail is in the middle, could you use a "wishbone" mast?! 🤪👍👍🇺🇸

@ no because on a proa the sail flips about 330 degrees during a shunt. It would not fit through the middle.

​@@markpalmquist the "wishbone" mast is like what is used on a sailboard, it can flip virtually 360 degrees. 😁

Yes, it does take a while to understand a proa. The word shunt means to uproot a tree. In this case flipping the sail should be easier and faster.

@@markpalmquist agreed...sailing a proa would be almost like learning to sail all over again as it is....might as well try to make it handle better.

@@RulgertGhostalker I like the proa because the hulls are easy to make and it is very fast. The harder part is putting it all together and then taking it back apart. It is very popular for people who just roll it up the beach and leave it there.

@@markpalmquist yeah i don't have beach front property either.

@@TinyHouseHomestead 27”

You can go as narrow as 24” but then you would need to lower your center of gravity. If you want to stand up and paddle 27-28” wide is perfect.

@@markpalmquist I want to build one that is 8'x2'x9" to sit on! I think it would be fun! You could call it the "Pond Punt"! 😁👍👍🇺🇸

@@TinyHouseHomestead At that length and width the boat would sink deeper so it would be slower but would still work.

@@markpalmquist Should I increase the depth of the boat to 11"? 😁👍👍🇺🇸

You kind of need a CAD program to figure it out. First you find the center of buoyancy with crew and gear, then put the leeboard slightly forward of that, then the sails force is usually 5” in front of its center of area (for a sail that is around 75 SF). Put the sail’s force in line with the leeboard and the boat should be balanced. That works for a punt and scow. A canoe shaped hull tends to turn towards the wind so you would need to shift the sail 7% forward. 7% of total boat length.

@markpalmquist Ooooooo, yeah that's what I thought! 😱😁😝🤪🤣👍👍🇺🇸 Soooooo, "that looks good won't cut it"! 😁🤪👍👍🇺🇸

There is a big difference. I used a NACA foil, printed it out full scale and made a female shape guide. You can also try to shape a board by hand but keep in mind a 2:1 ellipse nose is much better than round and the taper on the back end should encompass a good 1/3 of the board. And leave a 3-4 mm wide, sharp, flat trailing edge.

@@TinyHouseHomestead what is WIG?

@markpalmquist WIG - Wing In Ground Effect Vehicle! 😁

@@TinyHouseHomestead I could put ground effect fairings on the crossbars. Good idea. It probably would not create lift till about 15 knots of boat speed but that is worth exploring.

@@TinyHouseHomestead yes, I should call it that. But the cotton I use is finer thread and I use TB3 on both sides rather than just the inside. The shellac primer I use sticks to anything, including dried Titebond. Then the exterior paint sticks well to the shellac primer.

@markpalmquist PMF is TightBond 3 and Cotton Bed Sheets! 😁👍👍🇺🇸

@@TinyHouseHomestead cotton bed sheets. That’s a great idea. I thought most people were using canvas drop cloth, the kind sold at Home Depot to put on the floor to absorb paint. Bedsheets would be much smoother and easier to cut with a scissors. Thanks for your advice!

@@markpalmquist well people are using whatever they can get their hands on, that's what we poor people do ! 😝🤪🤣👍👍🇺🇸 My mom taught me to use bed sheets because you can just tear them like bandages, she always tells me how they used todo stuff during the depression! 😁👍👍🇺🇸

Great! Plans are available at palmquistmarine.com

@@matthewmiller8297 thanks! It’s a work in progress but I got most of the stuff up that I wanted to share.

One of the pioneering British multihulls was named Crossbow it was designed by the pioneer of Trimerans and builder of the GB racers. The late Derick kelsall.. There's an experimental yatch forum online ...

Thanks for your input. If it works well then I’ll have to give it a name. Hopefully I can test it in the next week before the water turns too cold.

@@skaraborgcraft this smaller float only requires 1 crossbeam so by default it would be lighter than a Tri with 2.

@@MadRat70 a torpedo shaped float hanging under the skimmer is also an option. It would create more space between the bulb and the skimmer, most likely reducing drag. It’s much harder to make a bulb but definitely doable.

@@markpalmquist I do wonder if you're approaching this a bit upside down? Or are you keeping the planing surface above so that you maintain resistance to leeway with the submerged portion? I feel like you're still gonna be wave forming more than you would.

@ the skimmer is designed to work on the surface. The float keeps it above water line till speed is high enough for dynamic lift to become dominant. The skimmer will cut the bow wave but I agree, I’m not sure what kind of drag will occur behind the trailing edge of skimmer. The float is helpful when you are being blown backwards if you get stuck in a tack.

@@RobbsHomemadeLife thanks Robb. I am a member and get their magazine and have joined 1 zoom meeting. Only 1 of the members is interested in what I’m doing, the others are mostly only doing hydrofoil testing. So I’m on my own with hydroplaning. Every day I get another research paper emailed to me from academia but every single paper is on speed boat hulls. Sometimes I learn something new. For instance a double stepped hull is only more efficient at Froude numbers above 3 so that’s why my wedge rower did not work, I’m at half that speed. But it could work on a sailboat. Eventually when I get a bigger sail rig and start beating beach cats I’ll get some attention. I have faith, I just don’t have a big budget yet.

Also, they are all boomers and have known each other for decades, I’m Gen-X. I would love to go to their trade show in England sometime and meet them in person.

I don’t have access to a wave tank but will ask around.

@@markpalmquist "I don’t have access to a wave tank but will ask around." I don't know the procedure, but if it is a novel design, university operated facilities may be interested to look at the features, perhaps solely to compare observations to computational models...

@@christophmahler Sounds good. I’ll try to find a university with a tank.

@@markpalmquist I recently noted also the internal software by 'DMS Marine Consultant' that claims to rapidly calculate a large number of variations in hull design, evaluating an optimum of desired features. As with external campus research, I don't know if this service is feasible on a small scale development, but contacting will clear that up as well (an unconventional design will certainly make for good conversation).

@@christophmahler I just reached out to the head of the hydrodynamics lab at the University of Maryland, my home state. Thanks for your advice.

Which Bolger book do you have? I have Boats with an Open Mind

@@markpalmquist Yes that's the one with Loose Moose/Advanced Sharpie Design, the Micro Cruiser is just a smaller version of the AS and can be googled.

@@markgallagher1376 😂

@@wojomojo it’s similar but different. When it dries it feels like rawhide. Shellac primer will stick to anything. Then the exterior primer and exterior paint fully make it waterproof. The cotton soaked in TB3 is less likely to have a pin hole. When using epoxy there can be a tiny hole somewhere where the epoxy refused to stick to. TB3 never does that. Also, TB3 when dry is flexible and not brittle. So your boat will be more like a rotomolded HDPE hull.

If it prevents a big stern wave it should reduce drag. I agree it should be interesting😀

@@ButterflyMatt thanks!

Thanks! It’s a small lake with small waves. It probably would not work as well in bigger waves. But it was primarily a test for the sail.

The holes will be to let water that came over the sides drain out. So basically now, because both the front and back halves of the boat will be self draining, it’s more like a SUP with side rails. I could take this to the beach and cut through the surf without sinking or filling up with water.

Also, I don’t expect any water to ever reach the inside cavity once I prime and paint it.

Extruded, yes, sorry.

@ that foam really stiffened it up. I guess it acts like a bunch of little I-beams or box beams.

@ it’s magic 😀. A 5 sided box is quite flimsy but add side 6 and you have a torsion box. It’s stiff like a guitar body. Yes, it adds triangulation. You could cut the middle 1/3 of every side and it would still be stiff. That’s why my mast step box did not break. It has 6 sides with a few interior holes.

@@Digne1d thanks. Another option is to add 2 more fins towards the from of the pivot arms, so there are 4 vertical fins. Penguins swim very fast under the water because their bodies accelerate and decelerate water without creating any waves. Boats on the surface create waves which is lost energy. Submarines are much faster when fully submerged. So a faster boat would be a catamaran hull with very slender hulls. Regarding prone position, I’m not sure how the arms could move if on your stomach unless you are on a narrow bench. Combining arms and legs together is a good idea but legs are better at pushing and arms are better at pulling.

@@markpalmquist The prone position would be like swimming but the head would always be above water. The arm & leg action would be like a front crawl or butterfly or combo but as you mentioned reduce the surface waves. Well, side stroke has less waves but you're not exactly prone and forward action is not smooth.

That would work well at high speeds but not so well at low speeds. But if you were trying to go really fast it would be a good idea. The genius of the Wingmaran is you shift weight from the displacement hull to the planing hull automatically as the speed increases.

@@RulgertGhostalker yes

@@SuperBrokenWindows thank you. The only reason I can’t yet recommend it is because I have not had any of my boats in the water for several days. I think with a hi grade primer and marine paint it might be fine. I just don’t want to make any claims that I can’t back up. I could make a small model and stick it in a bucket but salt water has microbes. Tropical waters ate a few of Magellan’s ships, only 1 ship made it back to Spain. So all I can say for certain is that my day boats have had no issues. Also, if I was to build a boat to race for 4-5 days I would upgrade to marine ply.

@@markpalmquist Ah, that's fair, I can definitely understand not wanting to make guarantees when you're not totally sure of performance. The other modifications definitely make sense as well, thanks!