Powerboat to Sail

[Delaney]

Don't laugh and don't tell me to just buy a used sailboat, but try for a little useful advice. I have an old lt wt 18' alum powerboat, 750 lbs, with a 17' LWL and bought a mast at a yard sale. Looking at the hull and rounded chine I thought it might make a descent down wind sailor for messing around. Going to put a motor on it when finished fixing it up, about a 50 hp, but thought this idea would be fun too. I am going to put a 6' long x 6" deep keel on it made out of 3/8" alum anyway to add stability while fishing and thought this might also make it more sailable.

Obviously it won't sail all that well, but George Caulkins made a sail version of his Bartender design and it sailed okay according to him. I have a 20' carbon/AL mast and figure making a poly tarp sail should not be too bad.

So how do you all think the hull would sail? You all are the experts, pictures attached.

[stubby]

The short answer...

No it won't sail well.

or alternatively you could buy one of these. It would sail just as well and do even more stuff.

[PAR]

The Bartender has a substantial skeg which helps to some level with George's sailing rig.

Sure, you can put a sail on your powerboat. It's not going to sail well even if you add some sort of appendages to steer with and pivot on in turns. Naturally, these will be in the way come powerboat use time. BTW a vertical 6" fin, mounted under your boat will not do a bit of good for stability, though it will help tracking and to a less degree sailing.

Why would you want to sail at 4 - 5 MPH when you can crank up the motor and blast along at 30 MPH?

[messabout]

Par; the OP has an idea of questionable worth as most of us agree. But you jolly well know why someone would want to move at 4 or 5 knots rather than blast along at 30. I do not need to refresh your memory with the virtues of quiet tranquility or to remind you that one can appreciate the natural wonders better at 4 knots than at 30. OK if you are in a hurry to make the 5:30 commuter train to Westchester County then you'd better go faster.

The keel idea is not necessary for the power boat and it might be a disadvantage especially when loading onto the trailer or splashing around in very shallow water. The sail idea has limited usefulness except down wind and then the boat will be slower than Par suggested unless you put up a lot of sail. A lot of sail will be a PITA. The OP has a noble idea but it aint gonna be worth the trouble.

[BATAAN]

If you do this, you'll learn more about sailing than hours on these forums. Set a budget of $100 or so for the job and have fun... in safe waters, with a backup plan and life jackets and pump and anchor, radio, cellphone etc.... just in case.

[PAR]

A really big umbrella woulds pretty good down wind. Delaney, you have to expect some level of harassment from the gang here, as you suspected it's a marginal idea at best.

You can employ a sailing rig and possibly drive into beam winds with a small keel appendage, as you've described, but it will be a lot of work for a 4 MPH top speed.

Have you a mast, sail, boom, rigging and other related equipment on hand?

[CatBuilder]

Isn't anyone going to mention that he might need ballast?

[thudpucker]

I wish we were closer I'd save you a ton of money.
I'd love to sell you my Ranger Bass boat with the 85 hp OMC and a great trailer.

You could make a Drop center board out of the Ranger.
Put the 85 On your aluminum and sell the Aluminum/Mtr/Tlr for all you have in your sailing project.

[mydauphin]

If all you want to do is sail and don't care much about anything else - got an idea. Try a kite sail. You won't need a mast, ballast or keel. Tie sail to center of boat you control sail via hands and rig it to steer boat with your feet. It is a crazy idea, but something I would try if I had time.

[CutOnce]

It's fine for us to criticize the idea, but it will get one more person on the water without noise. He'll probably have more fun trying this that he would not trying it.

I'd suggest a leeboard of some type that could clamp to the side of the boat instead of welding a long, shallow keel to the boat. It will work better and not cause problems with resale of the boat later.

Go into this with the idea of having fun and not worrying about nit-picky performance - with a leeboard, some type of rudder you will be able to sail at least down and across the wind - and maybe if you are lucky you might be able to claw your way up wind slowly.

Have fun, don't spend a lot and ignore all the experts sitting on the shore while you are on the water. You will have more fun, learn more and be able to drink a beer while they are typing in their basements.

--
CutOnce

[latestarter]

Originally Posted by CatBuilder

Isn't anyone going to mention that he might need ballast?

With it being 17' lwl treat it like a large dinghy and add a trapeze, also try lee boards, you don't need to alter the hull below the waterline, which will be better if you go back to power.

[CatBuilder]

Ha ha ha! A trapeze would be great!

In all seriousness, I mentioned it because if he's barreling along downwind with a standard rig in that thing and no ballast, then makes an abrupt turn in either direction, he's broaching.



And... I don't know what that thing has for flotation, but if he does broach it, he'll fill it up to the rail with water if he doesn't just go turtle.

Just thinking of some of the safety side of the plan here...

[summer suite]

I have a 30' searay I plan to put a removeable mast on, power up wind and sail back. out of fuel, or somthing different, it will be a sailer but maybe i can dock at my sailing club?

[PAR]

He doesn't have to worry about ballast folks, unless he installs a very tall, large area rig. The engine will keep him in fairly good shape. A small rig could help with fishing and also with steadying her down in beam seas. It's not a bad idea, just not especially practical, though this does depend on Delaney's goals and desires.

[Delaney]

Great input guys and it is something to just mess around with and have fun. Definitely not going to spend much on it. I like the leeboard idea and of course a rudder. Do I need two leeboards or just one. The boat is made much better that modern al boats as it uses aircraft al and has floation all the way down the sides and in the bow area.

What about the bottom shape? Isn't the rounded bottom transom better for sailing? If I had a deep V I wouldn't really consider it, but this boat moves very easily in the water. I know a guy with a 25 hp on one and with three people he does about 22wot and cruises at 12-14. Actually 4-5 mph would fine with me as it is just a for fun concept. I am not worried about broaching as I have sailed some and would not be carrying enough sail to cause a broach in reasonable conditions.

What size sail area would be reasonable? Thanks for humoring me on this and the suggestions.