Raidboat Pacific Proa

Discussion in 'Multihulls' started by BCowan, Sep 2, 2020.

  1. BCowan
    Joined: Aug 2020
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    Location: Colorado

    BCowan Junior Member

    The long and short is: the Everglades Challenge has been on my "bucket list" a few years now and I'm aiming to finish in 2022 or 23. Im about 6 months into the planning and designing a raidboat pacific proa to build in my garage. Im looking for comments and suggestions, and answers to a few specific questions. I hope to stoke some conversation and would love trade ideas and hear what other projects folks are working on too. Ive added a couple pics of the current model and scratch drawings, with lots of coloring help from my 2yo.

    I am reading with gusto some of the many posts here about the EC and proas, multihulls design, cutting-edge technology and building technique (and things WAY beyond the scope of what I envision), and have gleaned much advice and information already. Fascinating stuff, lots of passionate people, great ideas and experiences, and WAY too much animosity in some threads. Still, totally blown away by the skill that goes into the boats that have been designed and built, sailed and raced, sometimes with win-or-crash style!

    So the current iteration of my proa is just that, and Im not attached to most of the ideas. Ill spell out the details currently incorporated and im all ears for suggestions. To any naysayers or dissuaders- its just for the challenge of it. I have no doubt that with a bit of training, prep and luck i could finish the EC in various craft, but thats only part of the point. Im looking for a new and creative project to finish and to learn to sail in a new way and the EC is a real proving grounds! I have the experience for all kinds of adventure travel, ive built and rebuilt a handful of dories and my one-off canoe yawl. Ive heard lots of warnings, understand the nature of the challenge, and will certainly acid test the boat before such an adventure. I posted on the watertribe forum a couple weeks ago seeking ideas and advice and got lots of good and helpful feedback, and the acknowledgement that pursuing proas is a sign of mental derangement.

    General plan for the Proa-
    - Bomber sturdy built with a flexible enough beam
    - as lightweight and "high performance" as is realistic given the specs and construction methods
    - bulletproof simplicity
    - shallow draft as i can get.
    - meet and exceed rules and expectations to pass muster with the EC Chief.
    - carries a moderate amount of gear, equipment and 2 people, im thinking 350# people, 350# gear all up with rigging, camping gear drinking water etc
    - logistics and ergonomics for day-sailing solo
    - alternate propulsion setup, maybe hobie mirage peddle drive, oarlocks and rowing positions, a couple paddles for sure.

    So the basics:

    Mainhull Vaka will be a sharpie hull, flat bottom and slab sides, trapezoid amidship. Long-ish around 22' with about 12" wide flat bottom of 1/2" marine plywood. Probably 30" widest point at the gunwales. Im thinking fairly full ends and some freeboard at the ends, though not too much windage. Im still undecided on the exact length and amount of rocker, probably 8". It's the speed versus agility question that im stuck on. So the big question- What length, width and rocker might be the best compromise for the vaka? I have been warned against a 24' megayacht in the EC, so the decision is how much to cut off.

    Clearly there are different schoools of thought between the Harryproa's long sleek hulls and Russel Brown's (and CLCs mbuli and madness) bigger volume bows. The wavepiercing bows look raging fast, but my proa is already going to be a wet boat to sail anyways, and mainly, im just not going for maximum speed alone. In the EC particularly i need to be more agile and maneuverable and a significant rocker seems mandatory in choppy waves.

    I'll radius the chine, and plan to make the bottom an increasing V-shape that flows into the bows and stems. I think a V toward the bow will soften the wave slamming which apparently is a problem in many flat bottom boats, though mine will be only 12" at the widest. Seems straightforward to solve this with some curved cuts down the midline so the panels come together below the bows, a'la many CLC craft. I'll stitch-and-glue the ply bottom to sidepanels of plascore and cedarstrips. I bought a pallet of 11mm plascore panels years ago and 3 panels joined so i get the most out of a curve and shape, laminated flat with cedar strips makes 2 side panels curved and about 24" x 24'. Bent around the bulkheads and some temporary frames to the stems, filleted, seamtaped, and glassed inside and out. The middle third (8') of the vaka between the cross beam attachments and mast steps will be a raised-floor self-draining cockpit footwell over top of 6"-8" of buoyancy foam. I'll need to decide where to drill holes for drainage, maybe in the floor around a hobie drive slot. The bows will have bulkheads for large enclosed compartments, hatches for gear and inspection ports toward the bows. I plan on a wide and fairly shallow leeboard foil mounted on the windward side of the vaka. Ive got a rudder assembly from a Hobie 16 and with a wide swing, they'll shunt and stay in the water until I hit ground and they kickup. They will still work to some degree when kicked up. These are probably pretty small rudder blades considering I'm looking at a 20'+ boat but I think with a schooner rig the rudders will not bemandatory at all times.

    For the cross beams and masts i have 6061 aluminum tubes. Pretty straightforward to add some seats and decking for a tent platform on the iakos. I think the skipper's seat would have my feet down in the cockpit and a "rail-meat" seats out on the ama, so sheets and tillers will need to reach. As for camping, I like harryproa's pop-up tent idea, but theyre expensive and frigging heavy. The aluminum tubes the iakos are pretty stiff, and have incredible resistance to flex fatigue. At least one of Rael Dobkins proas have a third I-beam stiff Sampson post beam and i dont know if i need that.

    The 18' ama outrigger I plan to construct is a CLC night heron kayak to be built as a double-ender, what sexy lines! About 20" wide, nice bow lines so as not to get stuck dragging under a wave Should plane out and just be skimming when well underway and not overloaded. Might be some cargo space for a little more windward weight. Ive already got the plans and a buddy's cnc router that might help. righting moment will be from some day gear and two butts on a seat over the ama. The kayak is rated for 300# which may not be enough for two seated. Im not into the harryproa big weight to windward school of thought on such a small craft, but i see how it makes a safe big boat at sea. With the EC capsize risk, which is not trivial, i wouldnt want a loaded ama holding my proa turtled. We will be sure we can right it at sea, there are various techniques to pry one back upright. Grillabongquixotic's blog on wordpress.com describes some of his travel along the central american coast in his proa, and how he recovered from a couple holy$#!+ offshore capsizes.

    -Schooner Sailplan-
    Im partial to balanced lugs, mainly because my yawl has a 125sqft sail and im pretty comfortable with it. Halyards hoist, downhauls act like vangs, and only the mainsheets will need move while shunting. It gets some sail area in front of the masts, is easily dowsed, needs shorter and cheaper masts, low stress rig with mostly only compression in the mast, easy to slab reef with a tack hook and clew outhaul. Im thinking fairly high aspect rigs ~75sqft each, basically an Arctic Tern sail with the aft end of the boom high for visibility. Ill add deep reefs for slabbing each sail at 30" 60" 90" above the foot. With the third reef in, the boom and yard might be 12" apart at the tack and throat.

    A tierod between the masts makes bow stays unnecessary, and allows the aft sail to swing over the bow in the backwind situation. I dont have the money for carbon or freestanding masts, I think an adjustable windward stay will be enough from each mast to the ama center like a big V . The windward stay tensioner will cant the masts in heavier wind. Tensioner would be released along with sheets in the event of an impending capsize. I'll add a mast float if needed after capsize/turtle testing. The masts and tierod will be welded sealed and will float.

    Anyways, the CLC S'wester kit is approaching done and will be out of the garage by years end, then im gonna get after a proa build. Im all ears for advice, suggestions, links to other projects, etc. And thanks! Be safe out there. Thanks in advance.
     

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  2. peterbike
    Joined: Dec 2017
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    peterbike Junior Member

  3. BCowan
    Joined: Aug 2020
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    Location: Colorado

    BCowan Junior Member

    Yes! - lots of inspiration from the Harryproas, and this one in particular. Still, Ive been warned against a 25' megayacht in the EC, and i just don't know how well the camper pod proa would sail in 12" of water with those long rudder partially kicked up.. The blade rudders are very efficient and likely the boat is agile enough for my needs, the hulls are incredible, carries plenty of weight for my needs. Nonetheless, I just dont have the finances for that much carbon, freestanding masts, vacuum bagging etc. Im not looking to win, just finish in style with enough gas money to get home. Thanks for the link.
     
  4. Rumars
    Joined: Mar 2013
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    Rumars Senior Member

    First thing is to make sure you have enough underwater volume to float the required weight, proas don't like to be overloaded.
    I would ditch the 1/2" plywood and use 6mm or the plascore, both with two or three stringers. Then glue XPS on the bottom and sand it to shape to get the required V shaped bottom profile you want and put a layer or two of glass over it for stiffness and abrasion. That way you simply build a straight box and have complete freedom for the underwater shape (rocker is sanded into the foam and can easily be altered after trials).
    Ama same thing, plywood spine with shaped and glassed XPS sides.
    Big advantage of this construction method is that even if you scrape or hit something no water can come in and you remain afloat.
    I would also fit a safety ama (instead of a pod), also increases deck area.
    Make the masts freestanding, no need for carbon, wood or Al is ok. Lugs need stiff masts anyway, no need for stays or the tierod. You need aprox. 10% total lenght bury (between partners).
    For camping look for an inflatable tent, that is one where the poles are inflatable tubes, you just spread the thing on the trampoline, secure the edges and pump it up, it's self errecting.
     
  5. BCowan
    Joined: Aug 2020
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    BCowan Junior Member

    Incredibly helpful Rumars. Plywood is heavy, I really want a better option, and the XPS may be just the thing. Shaving and sanding foam seems easier and lighter than what I have in mind. XPS 150 is sold in Home Depots in the USA, but I wonder if its the density/grade/quality that is suitable for boat building like this. Ill look into XPS foam and see what I learn...... The advantage of hitting something and not worrying about a hole and a water leak sounds great. Sand and mud in Florida is one thing, but I sure wish I had that type of construction with foam on the boat we sailed around in Maine where we really nailed some rocks (my canoe yawl now has a full length kevlar skid on the hull)

    When you say 10% bury, I think you mean the insertion depth of the mast into the partner? a 16' mast needing ~20" seems about right. I do have a couple backpacking tents with snap poles, but an inflatable structure seems really simple quick to setup. The commercially available car-rooftop popup tents such as the Tepui weight upwards of 180#. The harryproa camper is awesome, but spendy.

    A free standing mast it can be. Is there not much advantage to canting the rig windward when in heavier wind? It would be no worries in a backwind situation where the rig otherwise might land on our heads. Seams like it could be just a tacking outrigger then....

    And i have toyed with a safety ama idea, and found a couple YT videos of them in action. I would like to use my Duckworks inflatable beach rollers securely attached as a safety ama, mainly for the capsize protection and partly to store the rollers inflated.

    Lots of ideas, I cant wait to explore these possibilities, thank you for the input.
     
  6. Rumars
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    Rumars Senior Member

    You are not using XPS in any meaningfull structural way. It is only there as a former and buoyancy. Strenght has to come from elsewhere (your plascore/plywood box). If you want structural foam you have to go to at least high density PU. What plascore do you have?

    Yes, bury is the distance between partners, commonly called so because it is the part "burried" under the deck.
    Canting the rig will move the CE and doing it to windward makes the boat more stable but what sense does this complication make on a lug rigged schooner? You achive the same effect by reefing. If you use a crabclaw then yes, canting is a highly desired feature.

    Safety ama from inflated beach rollers is no problem. Just use two poles set apart so that the rollers fit in between and straps to hold them in place.
     
  7. BCowan
    Joined: Aug 2020
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    BCowan Junior Member

    Interesting about canting a crabclaw sail and i certainly see why it's useful with a sail that is not conveniently reefed, and i do not see that it is necessary on the lugs . I've spoken at length with my sailmaker about all sorts of things, including the challenge of reefing a lateen. Seems that some schemes for a reefing lateen have been devised, but none are 'tried and true'. A reefing system is mandatory in the EC, which is part of the reason I'm entertaining the lug idea. I like lateens more on proas for the preservation of the style and proportions of the rig with the boat, if not the convenience.

    Come to think of it, it is nidacore panels that I have. 4'x8' x 11mm (1/2"). Plastic honeycomb with a thermowelded scrim fabric that epoxy bonds to well. It's soaks a lot of epoxy on the first coat and is essentially unsinkable once laminated on both sides. Super easy to work with.

    And yes, safety ama for sure, I've looked at several ways folks have incorporated one, and im sold on the idea. I still dont think its a guarantee against a capsize, and I won't depend on it as crutch, but it seems like such an important proa feature. Still, gonna practice capsize recovery with it all rigged up and loaded to see what it see what it takes get back upright.

    And sincerely thanks again for pointers, this is already incredibly helpful.
     
  8. Rumars
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    Rumars Senior Member

    I tought you had already finished panels. I would keep the honeycomb core for more worthy projects and buy 4mm or 6mm ply for the proa. Probably cheaper overall and not really heavier, plus simpler to work with.

    Reefing a crabclaw is possible, the trick is having the upper spar tethered to the mast and the stay to stabilize it in the reefed position. Achieved by a ring sliding up and down the mast and an additional adjustable stay. The reefing range is limited, you will not have three easy reefs, but two sails of different sizes each with a big reef is a good alternative. Pictures: Reef that Crab http://outriggersailingcanoes.blogspot.com/2013/09/reef-that-crab.html and original location with better details but in german Deltasegel: Reffen und Segelschnitt - Seite 2 - Multihull-Forum http://www.multihull.de/forum/viewtopic.php?f=6&t=158&start=10
     
  9. Zilver
    Joined: Nov 2007
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    Zilver Junior Member

    Hello BCowan,
    A way to reef a lateen rig is the "zipper reef" , an idea from Gary Dierking.

    The Zipper Reef http://outriggersailingcanoes.blogspot.com/2013/01/the-zipper-reef.html

    I have used such a reef and it works good. I constructed it by first tapeing and sewing the zipper on the sail, and afterwards (carfully) hot kniving just in between the zipper curve. A thing you have to watch out for is attaching the zipper on the sail very loose (difficult because the zipper is in a curve), else it will form a ridge/wrinkle in the sail.
    Greetings from Amsterdam, Hans
     
  10. BCowan
    Joined: Aug 2020
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    BCowan Junior Member

    Thanks Zilver, Ive gotten lost in the links that you and Rumars have provided, very interesting. I recognize several of the names that have experimented with proas in the last 20 years, but there is so much out there on the internet in blogs, pics and videos, that I have not seen. I do really like the zipper option and will ask the sailmaker about it. I still think a lug schooner rig will be best for me, though if I was going with one sail, I think it would be a lateen with this scheme for reefing. I have Gary Dierking's book on outriggers and there are the specs for a couple boats, the T2, and Ulua, etc. I am looking for a bit bigger boat, so am designing my own hull, but borrowing all the features I can. Sjunting a single lateen still takes moving the yard from bow to bow, which is time consuming and tedious if your are short-shunting up a channel and doing this multiple times. I see the lateen as a disadvantage in this regard compared to the lugs I have in mind; I would prefer to stay seated and just pull strings instead on clammering all over the vaka to reset the rig. Shunting the lug schooner rig only requires releasing the sheets and then pulling in the opposing sheets, no moving of masts or yard. I still wont be as quick as tacking but I think much more efficient than anything I can devise. Maybe Im wrong though........ive been through multiple multiple rigs and models. Marconi rig with roller jibs, a 160sqft menace of a Gibbons-Dierking rig, flying genoa schooner etc etc. I havent commited to anything yet, but I really like my balanced lugs.
     
  11. upchurchmr
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    upchurchmr Senior Member

  12. BCowan
    Joined: Aug 2020
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    BCowan Junior Member

    I appreciate the suggestions and i have thought long and hard about mbuli, either the plans or a full kit. As I mentioned, lots of the inspiration for my proa comes from that design. However, John Harris or some other folks from CLC in the 2001 EC well-demonstrated the fact that dagger rudders are generally unfit for Florida coastal sailing. I don't want to start modifying a design immediately 'out of the box',and i want an open boat with tent space for two and not a coffin for one. And it's just my opinion on freeboard shape, but I think it has too much windage on that angular plumb bow.
     
  13. Boatguy30
    Joined: Dec 2011
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    Boatguy30 Senior Member

    There is a tacking pros/outrigger here in Fakarava. Not quite sure what it's for, I'm guessing a guy made a bunch of money on pearl farming and spent it building this little toy. All high end Karver fittings on dyneema, dyneema netting etc. Has a small cuddy probably about 24' and hauled ashore on logs. Really nicely done, has a leeboard and kick up rudder. Will get a pic tomorrow
     
  14. BCowan
    Joined: Aug 2020
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    BCowan Junior Member

    That's excellent, i would love to see pictures. I had to lookup French Polynesia to figure out where you are too, incredible.
     

  15. Clarkey
    Joined: Aug 2010
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    Clarkey Senior Member

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