Versatile Kayak/Trimaran Questions

[60buckscash]

Hello everyone! This is my inaugural post on here. I have ben lurking around for the past several months and have finally come to a point where I have some questions I have not found elsewhere.

I am planing on buildinga Laker 13 kayak and am hoping to turn it into a small sailing trimaran to explore some of the coastal areas south of Tampa, Fl. I have worked out on paper the brackets I will instal on the bulkheads that will come up through the deck that I will attach the outrigger arms to.

The pontoons will take a deeper V profile that will hopefully minimize the use of a lee board. Where would be a good place to look for plans for these? Storage for a small tent and some other supplies inside of them would be great as well.

The proposed rig on this will be a balanced lug sail. I am wondering what size I should be looking at for mast height and square footage. What type of additional reinforcing should be done at the mast step for this?

Thank you for any help you can offer with this.

[Dan St Gean]

There's lots of guys at watertribe doing just that with a variety of kayaks and canoes. Some good examples here as well. Off the shelf Kits are available from Balogh (BSD) and CLC. Check it out. Don't bother going too crazy with the sail area as you'll most likely never get out of displacement speed with a 13' kayak based main hull.

Dan

[Cuyahoga Chuck]

Check these folks out too.
http://www.kayakforum.com/cgi-bin/Building/index.cgi

[keyhavenpotterer]

Loads of info here http://www.solwaydory.co.uk/ and here http://www.songofthepaddle.co.uk/for...Sailing-Canoes

On Facebook as well http://www.facebook.com/groups/152444938788/ This japanese sailor seems to have produced something very like you have in mind

http://www.facebook.com/photo.php?fb...type=1&theater



The interest and activity in outrigger open sailing canoes is very buoyant at the moment here in the UK.

Brian

[JoeFarina]

Loads of info here http://www.solwaydory.co.uk/ and here http://www.songofthepaddle.co.uk/for...Sailing-Canoes

On Facebook as well http://www.facebook.com/groups/152444938788/ This japanese sailor seems to have produced something very like you have in mind

http://www.facebook.com/photo.php?fb...type=1&theater



The interest and activity in outrigger open sailing canoes is very buoyant at the moment here in the UK.

Brian

There is a post at smalltrimarans dealing directly with this issue also. It mentions a craft being developed at CLC that is a true small tri as opposed to being a kayak with double-outriggers/sail - http://smalltrimarans.com/blog/?p=8343

[Chris Ostlind]

I like that CLC is looking at the potential for a boat of this type and preliminary lines drawings show a boat that will be sleek and probably a real blast to sail at lower speeds.

I'm happy that John Harris is venturing into fresh territory with this boat and look forward to seeing it out on the water.

[smallyachtsailor]

I build both kayaks and small sailboats, and some years ago built a sail/outrigger rig for my 16' sea kayak. In spite of a fairly easy-to-turn kayak hull, I soon was not happy with the tacking abilities of the rig, and built a 10' hull and turned it into a miniature trimaran (which I could still paddle reasonably well).

Now for my two cents:

My little tri has 8-foot long sharp "V" amas (triangular in cross-section), and while it can go to windward without the centerboard down, the tiny C/B makes a HUGE difference--well worth the few pounds weight it added.

Dan St. Gean is correct about keeping the sail area small. Unless you have a planing hull, you won't need much. My trimaran weighs about 70ish pounds (plus my own 180 lb. carcass) and its 37.5 sq. ft. of sail gets it up to hull speed in light winds of between 5-10 mph. While certainly not a fast boat, it does quite well against similar length boats.

My tri has a small two-sheeted jib that I backwind during a tack to help the boat around--I almost never get stuck in irons. I'd highly recommend a small jib for that reason alone. Also, be sure you design your amas so both are out of the water when on an even keel. It'll help greatly to balance the boat and hold them out of the water--with sailing speed downwind--and with your rate of turning while tacking.

I'd recommend not using your amas for storage. Any weight you put out there will inhibit your turning ability--much like concentrating weight in the ends of your main hull. Even with only a 10' 4" long hull, I find I've got plenty of storage behind my seat--enough for a few days worth of camping gear--and more than enough for daysailing.

Best of luck with your mini-trimaran, and I hope you have as much fun with yours as I'm having with mine.

[Chris Ostlind]

Canoe and kayak design guru, John Winters, once told me that when it comes to sailing boats of this type (principally paddled craft) one needed to decide, early on, as to whether the boat was going to be fish, or fowl. Kind of a crafty way of telling me that I had to decide if it was gonna sail, or be paddled, as its vital comittment in design. Over the last 14 years of doing this, I have found that one can very carefully tiptoe along the demarcation line to arrive at a boat that is successfully both creatures... but it's really dicey with dozens of little decisions that complete a final boat of this type. Most off the shelf hulls are not going to give you the best of both worlds.

The 36-38 sq. foot of sail area idea is a generally good starting point for any of these boats. I have found, through trial and error, that a 56-60 sq. ft. sail is a much better option if properly designed and located. With the bigger rig, you open-up lots of really great sailing in very light airs and it can always be reefed should things get testy. This same great sailing is not so much a part of the experience with the smaller sail area at hand. All this came about because in light air, one can generally paddle a lot faster than one can sail with a small rig and you can make much better speed over ground in the precise direction you want to go.

Your choice of a boat that is 13' LOA puts you just shy of the optimal length for a recreationally paddled craft with an efficiently designed hull. I'm not going to launch into another rant about planing and small craft that might be capable of same. Instead, I would suggest that your sailing hull design is best kept in the very skinny style of hull that allows semi-displacement types of efficiency, rather than concerning yourself with the planing question. For small boats, it's way more efficient and requires a lot less sail area to get the job done. This means an easier to handle rig and boat, less loading and stress on the foil appendages and gives you the grace to be more nonchalant while out on the water.

[smallyachtsailor]

I agree entirely with all that Chris said. With regard to wanting more sail area than the 36-38 sq. ft., I also mostly agree. Yes, my tri only has the smaller figure, but on days when the wind is too light for my tri, I take my 18-foot sea kayak out for a spin instead, so I don't usually need the extra sail area. However, with a 13-foot tri I'd certainly have more sail area than the 38 I have on my 10-footer--probably (as Chris suggests) in the 50-60 sq. ft. region.

[60buckscash]

Primarily the boat would be a paddled kayak for recreation uses. I am not looking to race with it.

I would guess that 70% of the time the boat will be a kayak exploring mangrove swamps and tidal areas around home. I also have a 12' sot as a sister boat.

The 13' length is a restriction based on where I would have to store it when not in the water.

I have no illusions of having a fast planing sail boat. Between my weight of 275lbs and a boat with sails and supplies of 100lbs I would just like to have a small "fun" day sailer. I think a great day would be getting a couple miles out to an uninhabited key, exploring around it while catching some dinner, and then setting up an overnight camp. (I can dream right?)

I will run with the 56-60 number for a sail with an appropriate mast height and a 9' long ama.

[Chris Ostlind]

Just make sure that you have enough all-up displacement, that your ama volumes are appropriate for the heeling moment that can be generated and that your aka length makes the best use of the intended ama buoyancy. A bigger rig on a small hull can be a handful if the overall balance of the design is not in tune with the power available. Small boats such as this can have a tendency to bury the bow when reaching and running, so a good spray skirt is essential. I'm sure that you'll have a blast day in and out with your boat, but it's good to be aware of the design limitations before chugging off to an offshore key.

Most of all... have fun, whatever you do with the boat.

[smallyachtsailor]

My amas are eight feet long, triangular in cross-section, and displace about 65 lbs each--if that helps you at all. That's enough to get well up to hull speed on my 10' main hull. I stop pushing the boat once my lee ama is awash--not much point anyway since the stern is starting to settle with the boat at hull speed. So that's 65 lbs displacement for each ama on a boat that weighs about 250 lbs or so all-up (with me in it). I can easily stand up in the boat, but obviously can't sit on an ama and stay afloat. Don't forget to put some watertight buoyancy in the hull too, if you're going far from shore.

I spaced the akas and amas far enough apart and out so I can paddle the boat without clanking the paddle on them. I also curved the akas upward in part for looks, and in part so they'll be even more out of the way of paddling. Other than being a rather short boat its fairly easy to paddle up to hull speed. I balance both amas out of the water while paddling--it makes a big difference.

Here's a link to a few pics of my little tri, first as a sail rig installed on my old 16-foot sea kayak, then with the 10' 4" sailboat hull.

http://www.msc.wildlifeofct.com/sailboats.html

I didn't like the sliding gunter rig I first tried, so I eventually lopped the top off and made it a short-gaff rig. It cut down a lot of windage up there, and I never really noticed the loss of sail area. The boat also seemed to handle and sail even better. It balances so well I can steer it with just two fingers on the steering line (it also has a foot-bar for hands-free steering).

Let us know how your tri works out.