The small trimaran thread

[FleetPeet]

I understand building extra strength in if you're considering upping the sail area at some time. All of my boats are very light and I love how they behave (perform?) in the water because of their low mass. I really think the extra performance you get from reducing the overall weight of a boat is often underestimated.

I'm trying to finalize the design so I can get started with the building this fall, hoping to dip it in the water by spring--but of course well-planned projects oft' go awry. I do plan on setting my half-built sailing canoe aside to make room and time for the trimaran. If I get stuff done to take pics of I'll try to post...good luck on yours too Pete

low mass sailrcraft are an interesting lot. They have those low wind advantages that leave heavier boats doin the bouy but tacking can be a little sensitive and so with pinching especially. I dont want to make it a dog but I dont ever want to fear the craft coming apart. So Im looking to strike a balance.

I think Im zctually going to continue with a leeboard and forgo the centerboard simply to save weight. That and its extremely cool watchin g an efficient leeboard cutting water. It dumbfounds me that my kayak sailrig can hit 7 knots on an averege 10 knot breeze and no vibration whatsoever in the board.

I appreciate your perspective.

Pete

[DavePont]

Marc,
Thanks for the welcome. This little tri was an experiment that's evolved over time.

Hi there, a few questions about your excellent tri: what was ama length? volume? overall beam? how was paddling with the double kayak paddle? what kind of rudder setup - pedal steering?
I'm interested in building something along these lines, hence all the questions!

cheers, Dave

[smallyachtsailor]

Thanks for your interest Dave.

My smaller trimaran's main hull is 10' 4" long, about 28" beam at the deck (about 24" at the waterline), and has a slight V bottom with single chines. The centerboard is about 1x2 feet and the rudder is controlled by lines to a rotating footpedal crossbeam. The hull alone (with the C/B) weighs about 40 lbs. Its all built of 3 mm plywood with frames and chine logs.

The Amas are 8' long and symmetrical, triangular in section 7" wide at the widest point, and 8" deep. They each displace about 65 lbs or thereabouts.

Some of this is sketchy because I don't have full plans for it--I just sort of built it from what I had in my mind.

Total sail area is a paltry 37.5 sq. ft, which actually seems to be plenty for my purposes. I think I said earlier that this whole rig started as a sail rig for my old 16' sea kayak. The rig was originally a sliding gunter/marconi, but I didn't like it so I cut it down to a short-gaff (I'm a fan of Wharram), which works great and is much more robust. All-up, the boat weighs about 70-ish lbs, so about 250 lbs with my carcass in it. In my area (SE Connecticut) typical winds are about 5-10 mph, and that's enough to get the boat up to hull speed, and get the leeward ama submersed. Once that ama is awash I let up on the sail power--can't push that bow wave any faster anyway. I never intended to make it a fast boat, but others on the water usually seem impressed, and I think I at least keep up with boats that have much greater sail area (i.e., beetlecats, etc.).

At first the boat would hang up in irons now and then, but I solved that by double-sheeting the tiny jib and I can't say I have had any problem tacking since then--I just backwind the jib. Personally I wouldn't build a tri now without a jib.

I've rarely had to paddle the thing since it moves along well even in light air. If I shift my weight a bit and get both amas out of the water I can feel the speed increase. And downwind I just pull up the board and shift my weight a bit forward. I did take some measurements and placed the amas and crossbeams far enough out and fore-and-aft so I could easily paddle the boat. It paddles ok for a 10' 4" boat--easy to get up to hull speed, which isn't a whole lot compared to my 18' sea kayak.

The overall beam is just under 10', making the tri nearly square. The crossbeams are laminated with 4 layers and are 1 and 1/8" wide and 1 and 3/8" deep.

The rudder is a kick-up. I sail in very thin water at times, so I often have the tiny board pulled up partway. Steering is a breeze. Two lines attached to the rudder with a yoke, and they lead down through the rear deck and around pulleys on each side of my seat, then foreward to a swiveling steering yoke. I can steer with my feet, or with two fingers on one of the lines next to my seat-the boat is perfectly balanced.

I know many would want to add more sail to it, but unless you increased the ama volume, or got the boat to plane, I don't think the sail area would be of much added benefit. You can only drive 10' 4" so fast. Even on 37.5 sq. ft. the boat often outsails its stern wave a bit--say, any time the wind is over 10 kts. The whole thing unbolts and fits on top of my VW--still leaving room for a kayak on the other side of the rack. It takes about 15-20 minutes to go from car to water or back. I also have a small wheel that locks into place on the rudder gudgeons so I can roll it assembled into (or out of) the water solo.

The tri is so tiny, once another sailor some distance upwind of me looked very surprised when I finally sailed up to him. He then confessed he'd been watching the boat and thought it was radio controlled--he was looking for the guy on the shore with the transmitter.

Any other questions--I'd be happy to answer.

Bob

[FleetPeet]

Thanks for your interest Dave.

My smaller trimaran's main hull is 10' 4" long, about 28" beam at the deck (about 24" at the waterline), and has a slight V bottom with single chines. The centerboard is about 1x2 feet and the rudder is controlled by lines to a rotating footpedal crossbeam. The hull alone (with the C/B) weighs about 40 lbs. Its all built of 3 mm plywood with frames and chine logs.

The Amas are 8' long and symmetrical, triangular in section 7" wide at the widest point, and 8" deep. They each displace about 65 lbs or thereabouts.

Some of this is sketchy because I don't have full plans for it--I just sort of built it from what I had in my mind.

Total sail area is a paltry 37.5 sq. ft, which actually seems to be plenty for my purposes. I think I said earlier that this whole rig started as a sail rig for my old 16' sea kayak. The rig was originally a sliding gunter/marconi, but I didn't like it so I cut it down to a short-gaff (I'm a fan of Wharram), which works great and is much more robust. All-up, the boat weighs about 70-ish lbs, so about 250 lbs with my carcass in it. In my area (SE Connecticut) typical winds are about 5-10 mph, and that's enough to get the boat up to hull speed, and get the leeward ama submersed. Once that ama is awash I let up on the sail power--can't push that bow wave any faster anyway. I never intended to make it a fast boat, but others on the water usually seem impressed, and I think I at least keep up with boats that have much greater sail area (i.e., beetlecats, etc.).

At first the boat would hang up in irons now and then, but I solved that by double-sheeting the tiny jib and I can't say I have had any problem tacking since then--I just backwind the jib. Personally I wouldn't build a tri now without a jib.

I've rarely had to paddle the thing since it moves along well even in light air. If I shift my weight a bit and get both amas out of the water I can feel the speed increase. And downwind I just pull up the board and shift my weight a bit forward. I did take some measurements and placed the amas and crossbeams far enough out and fore-and-aft so I could easily paddle the boat. It paddles ok for a 10' 4" boat--easy to get up to hull speed, which isn't a whole lot compared to my 18' sea kayak.

The overall beam is just under 10', making the tri nearly square. The crossbeams are laminated with 4 layers and are 1 and 1/8" wide and 1 and 3/8" deep.

The rudder is a kick-up. I sail in very thin water at times, so I often have the tiny board pulled up partway. Steering is a breeze. Two lines attached to the rudder with a yoke, and they lead down through the rear deck and around pulleys on each side of my seat, then foreward to a swiveling steering yoke. I can steer with my feet, or with two fingers on one of the lines next to my seat-the boat is perfectly balanced.

I know many would want to add more sail to it, but unless you increased the ama volume, or got the boat to plane, I don't think the sail area would be of much added benefit. You can only drive 10' 4" so fast. Even on 37.5 sq. ft. the boat often outsails its stern wave a bit--say, any time the wind is over 10 kts. The whole thing unbolts and fits on top of my VW--still leaving room for a kayak on the other side of the rack. It takes about 15-20 minutes to go from car to water or back. I also have a small wheel that locks into place on the rudder gudgeons so I can roll it assembled into (or out of) the water solo.

The tri is so tiny, once another sailor some distance upwind of me looked very surprised when I finally sailed up to him. He then confessed he'd been watching the boat and thought it was radio controlled--he was looking for the guy on the shore with the transmitter.

Any other questions--I'd be happy to answer.

Bob

Bob,

Thats genuinely well made, nicely conceived - a lot of greart lines on the craft. I too live in Connecticut, central... it looks like thats Mystic in the background no? Im familiar with the local waters and the 5 to 10 knot usual wind. Where bouts is the shallow waters you ply?

Id bet that would be a very good sailboat on the quite side of Monomoy Island with all the shoals and tidal flats.

Again, a truly nice craft.


Pete

[smallyachtsailor]

Yes that's Mystic in the background. Pretty shallow when the tide is out, as it is a lot of places along the coast nearby. I hit bottom far too often with the C/B to ever go with a daggerboard.

[FleetPeet]

Yes that's Mystic in the background. Pretty shallow when the tide is out, as it is a lot of places along the coast nearby. I hit bottom far too often with the C/B to ever go with a daggerboard.

Just got back from Newport - no multihull, just beachfront chair and beer. Fishing was nil but my location was a cove so....

What was and always is striking that far out east is the pristine color of the breaking waves throwing off this luminescent peacock green. Ahead of it is that virgin snow white broken wave of froth. The contrasts between the two never ceases to amaze me. LI Sound has it points no doubt but the moment the coast gets pure ocean water ciruclation - wow what a dazzeling difference.

It energizes and motivates me to finally have my sailrigged kayak completed again in trimaran form. The proa just didnt cut it.

From my beach chair my afternoon contemplation was all about the distant spinakers and mains'ls of far off regattas taking place - THREE at once on Saturday, two on Sunday. Id guess they were a good five miles out, maybe three. My Nikon 8x42s made good work of it. Havent a clue who won but it was entertaining nonetheless.

Had my craft been done by now I atleast wouldve taken a cruise out there within respectful distance.

Just talkin...

Pete

[FleetPeet]

Oh and my vacation wisdom...

FILA Skeletoes are superb jetty rock shoes bar none. Im adopting them as my kayak sailrig shoes as well. Rinse em in soap and water the days end, and they simply never smell or get yucky. Cant say that of wet sneakers. I had my strong doubts here, but that little rinse at the end of the day keeps em smelling like rubber and neoprene no matter how much low tide goo i step in.'

Pete

[Dan St Gean]

Well,

I just ordered the Strike 15 plans from Richard Woods. The more I looked at it the more I liked it. Several rig options, and a nice balance between a hot rod and a cruiser. I'll not begin building for a while, but it's fun to have made a chioce.

Dan

[JimD]

Well,

I just ordered the Strike 15 plans from Richard Woods. The more I looked at it the more I liked it. Several rig options, and a nice balance between a hot rod and a cruiser. I'll not begin building for a while, but it's fun to have made a chioce.

Dan

Just what you need, Dan. Another boat to build. Let us know when the plans arrive. Perhaps we can coax Richard to come back to the forum to offer his wisdom on the design.

[Dan St Gean]

Just what you need, Dan. Another boat to build. Let us know when the plans arrive. Perhaps we can coax Richard to come back to the forum to offer his wisdom on the design.

Actually, I've been casting off stuff for a while. Ulua--sold. Schade Expedition 19' kayak--sold. Tamanu--sitting idle for now, but can be assembled sans deck and rudder in about an hour using the Hobie 18 gear. Hobie 18--needs a four rivit mast step and new mast bearing, so it's idle too. The Hobie Wave is active at the lake however. I'm sailing it by far the most at present, but it needs 15-20 to be any fun.

Richard's Strike 15 looks like a nice compromise between hobie 18 speed and comfort and some drynesss and comfortable seating for cruising. Adding a quick fold concept without needing to lift or bolt anything, and I think it'll be a winner. It helps that I can use the crappy trailer I already have and just back it into the garage for the winter if I don't drag it down to Sanibel over the winter. Winter a year from this coming one that is...with coaching, teaching and three little ones, this build will be glacial even though it's a fast one from the prototype. Oh yeah, the prototype factor is really nice, and it doesn't hurt it should be lighter with more sail area than the Weta.

Dan

[JimD]

It looks like a serious little boat



And for more casual sailing a smaller simpler rig

[JimD]

Actually, I've been casting off stuff for a while. Ulua--sold. Schade Expedition 19' kayak--sold. Tamanu--sitting idle for now, but can be assembled sans deck and rudder in about an hour using the Hobie 18 gear. Hobie 18--needs a four rivit mast step and new mast bearing, so it's idle too. The Hobie Wave is active at the lake however. I'm sailing it by far the most at present, but it needs 15-20 to be any fun.

Richard's Strike 15 looks like a nice compromise between hobie 18 speed and comfort and some drynesss and comfortable seating for cruising. Adding a quick fold concept without needing to lift or bolt anything, and I think it'll be a winner. It helps that I can use the crappy trailer I already have and just back it into the garage for the winter if I don't drag it down to Sanibel over the winter. Winter a year from this coming one that is...with coaching, teaching and three little ones, this build will be glacial even though it's a fast one from the prototype. Oh yeah, the prototype factor is really nice, and it doesn't hurt it should be lighter with more sail area than the Weta.

Dan

I'm not so much casting off as consolidating and trying to make something useful out of bits and pieces from half finished projects. Zeno's Turtle, our new kayak proa is turning out to be great fun as a beach boat and I'm going to resist any urge to turn it into anything more. So the next boat will be the other kayak cut down the middle to make an asymmetric 15 foot beach cat. That still leaves a couple eight foot dory outrigger hulls to find a use for but in time I'm sure I'll figure something out. After that I'm going to have to wait for a bag of money to fall out of the sky before starting anything new or bigger.