Take 2 Sunfish—Make Catamaran?

#3
Believe it or not it has been tried. About 4 feet between the Fish with a PVC piping arrangement to hold the two togther and a conduit tubing arrangement like Hobie uses to control the Rudders. The Lateen rigs would smack into one another and tacking was just about impposible due to the greatly increased beam.
They went as far as replacing the rigs with sailboard rigs mounted ouboard on the Fish to give clearance and replaced the ball mount bases with stiff ones so the rigs could be controlled without standing on the decks. A lot more speed but again tacking/gybing was about a 1/2 mile circle...LOL
We did some figuring and the wetted surface of the fish was larger than that of a 14 foot Hobie. A 25 knot day broke up the experiment and the folks figured it wasn't worth any more tinkering to get it to work.
 
Thread starter #5
I dunno:

Both masts could have been yoked together using 2 white PCV "T"s (to look like a long PVC "H"),

At the union of the spars, they could have been joined loosely together to reduce the amount of time that the sails might hit one another (using thin, bendy, grey PVC)... yet allow some individual compliance.

Tilting the hulls slightly inwards would reduce the wetted area. (Heat and bend the white PVC).

Then find a really big lake! LOL
 
#6
I'm leaving my fiddly catamaran for the simpler, funner, Sunfish—but there's this thing nagging at me.

The very thought kinda defeats the purpose of a very simple hull and rig—and I've seen nothing on the Internet about it***.

But the idea still intrigues me. Two stayless rigs. Hmmm. Hmmm. Anyone tried it?

***OK, well, a Trimaran, maybe. :eek: http://www.boatdesign.net/forum/archive/index.php/t-2061.html
I am building a serious Sunfishamaran now. I have constructed composite crossbeams. I am using Prindle 18 rudders and a Trak 18 mainsail and jib on a 26' aluminum mast. I will try to upload some pics. I am rigging the mast today.
=-) PAD =-)
 

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A2

New Member
#7
Sometimes when you tell someone it can NOT be done, it makes them that much more determined.

I love the idea, and wish luck to NH1-PAD and hope that he keeps the pics, and hopefully video of sea trials, coming.
 

beldar boathead

Well-Known Member
#8
I am not a marine engineer, but why are the hulls so close together? Also, although I have only thought about this for about 5 seconds, why wouldn't the hulls be canted in the opposite direction to give some chance, however slight, of reducing wetted surface in a higher breeze. As they are, they will have more wetted surface as this "vessel" heels. BTW, I thought a Trac 18 had a small main. Will it have enough horsepower to move this weight and wetted surface???
 
#10
I think I might actually pay money to see a video of this going downwind in a decent breeze, maybe in moderate chop. You definitely have to post pictures.

I'll bet that with a decent outboard bolted to the rear crossbar this fish-cat could be interesting.

i
 

beldar boathead

Well-Known Member
#12
I think I might actually pay money to see a video of this going downwind in a decent breeze, maybe in moderate chop
i
I will pay to see that too. I think the only practical (if there is one ) point of sail in a breeze will be a reach. The effective beam seems too narrow to handle much sail area going upwind. Looking forward to seeing more progress.
 
#13
Has anyone done a Sunfish with an outrigger? A much smaller pontoon than a whole other Sunfish, and maybe a trampoline might be more suitable.
 

beldar boathead

Well-Known Member
#14
The ultimate would be a trimaran. Two Sunfishes fastened bow to stern as the main hull, with a Sunfish on either side on long arms as the amas. The put a massive rig, perhaps from a J-105 on the middle hull. Or just buy a Hobie 18 and probably go faster with a lot less effort. BB
 
#15
Hydrofoils would be best, which are moved into place with a lever in the cockpit area. (Lever engaged hydrofoils, hidden within the hull or mounted on deck, lever tensions the hydro-halyards and locks in place to hold the hydrofoils in the water)
 
#17
Wow! What a great exchange of ideas. I only want to make it go fast. I am an iceboater and the key is reducing friction and efficient use of apperent wind. I want it to get on a plane as quickly as it can. I hope to use the close hulls to act like a skimboard and the 8' beam is perfect to trailer without any conversions. Two people on the windward quarter should keep it sailing reasonably flat while on a plane. The Prindle 18 rudders are actuated thru a reversal pulley system which slows down the response speed from tiller to rudder. If you've sailed fast dinghys, when planing, speed is great enough to need to slow the response of the tiller. I totally expect a dog of a cat until I get enough wind to plane. Kind of like a shortboard windsurfer. Excellent for ripping reaches and power jibes. Oh, did I mention I windsurf as well? Almost ready for the "shake-up cruise".
 

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#18
Oh, I thought about capsize. When it's a monohull they say it "turned turtle". With the Sunfishamaran it will have to be "turned turtles". lol I think with a masthead float, the hulls should swing downwind and like a Hobie, act like a sail, helping to bring it back up. And besides, it's got two dagger boards. One person on each!
=-) PAD =-)
 

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#19
Hydrofoils would be best, which are moved into place with a lever in the cockpit area. (Lever engaged hydrofoils, hidden within the hull or mounted on deck, lever tensions the hydro-halyards and locks in place to hold the hydrofoils in the water)
I have though about a hydrofoil boat like the Hobie Tri-Foiler.I could make fixed foils on the bottoms of the daggerboards and push down and lock in place. Then fabricate a single foil rdder that adjusts at the tiller grip like a Moth. If planing doesn't go, I already have a book on how to design and build the foils.
=-) PAD =-)
 
#20
I have though about a hydrofoil boat like the Hobie Tri-Foiler.I could make fixed foils on the bottoms of the daggerboards and push down and lock in place. Then fabricate a single foil rdder that adjusts at the tiller grip like a Moth. If planing doesn't go, I already have a book on how to design and build the foils.
=-) PAD =-)
That's cool. I don't know how to figure out the fluid dynamics involved - the surfaces - the area - depth - geometry - and of course how to manufacture such things... but they are the fastest way to sail. (A stealth, hidden, system would be a great practical joke during a race. Although I wouldn't do it. ) It's interesting to think about. My wife might get on the Sunfish if I had an outrigger with a trampoline to sunbath on... not that I would be allowed to spend any money on such a thing!

Good luck PAD, I look forward to more pictures and videos!!!
 
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