Trimaran Conversion on the Cheap

I recently acquired, all for free, an old 70's speedboat (15' Crestliner "Muskie", bowrider trihull design - the old outboard doesn't work, hull is in great shape), a Prindle 16 in great condition, and an extra Prindle "parts" boat with hulls and extra mast in great condition. I have been having a blast on the Prindle with some multiday solo sail camping trips and some daysailing with my wife. My wife has never really loved the "excitement" of the Prindle in anything other than a light breeze, and with the recent addition of a baby at home, I've been pondering some options for some gentler, family-oriented daysailing and sail camping. I am currently a student and we have minimal income to lend to this sort of thing so buying a better outfit more suited to this task right now is not an option. Brainstorming this situation, I have started to ponder using the speedboat hull, my extra Prindle hulls, and the rig from my good Prindle as a converted trimaran...

I know that this isn't an ideal conversion situation, as the Crestliner is certainly beamier and a very different shape than the center hull on most trimarans I've seen. My question for you is if there is some reason, with my modest goals in mind (a stable affordable daysailer), why this absolutely wouldn't work?

Because I don't really have anything to lose--some modest material costs (foldable cross braces for the amas, a rudder/tiller, and I'm thinking about lee boards to not have to deal with building a case for a centerboard) and some time (I need a project to tinker on anyways), I'm excited to give this a try.

Any suggestions to make this project doable? Any glaring pitfalls that I might be missing?

Below are some photos of the hulls.
https://drive.google.com/file/d/0B3nDxYVQOTala2FzUkw4M0FkYUE/view?usp=sharing
https://drive.google.com/file/d/0B3nDxYVQOTalc3ZJWnlVV0hOSUk/view?usp=sharing

I'm brand new to this forum and have been digging deep into the vast knowledge and experience shared in these threads. Thank you for any help/wisdom you might have to offer!

 

Get a working motor and just use the power boat as a powerboat.

As a yacht it has too much wetted surface.... it's too fat, it will be bouncy and slow as a trimaran.

 

A power boat is an absolutely poor choice as a main hull in a conversion.
Too short and fat.
At least get a sailboat as a main hull, you will get the sailing gear also.
Most of those will be fat enough as to be a poor (slow) trimaran, but here is one that at least makes more sense.
http://smalltrimarans.com/blog/the-one-of-a-kind-austrian-soling-trimaran/

You may think the power boat hull won't cost much to convert, but you will get absolutely nothing if you try to sell it.

 

Thank you for the quick responses! I understand that this would not be a fast trimaran by any means. And I mean no disrespect to the sleek elegant boats that I'm sure you all build and sail.

However, these two hulls are what I have available. They aren't worth anything in terms of resale to begin with (for instance, a previous owner of the powerboat botched a terrible restoration job using particle board to replace the floor and and cheap house paint to repaint the hull. My neighbor ended up with it, and before moving he asked if I would be interested in it before he drove it to the dump... So now I have it and at least the fiberglass portion is still in good shape. And the trailer is perfect.) I don't want to sell the Prindle, though I wouldn't mind utilizing the extra hulls that I have and lending some of the rigging from my good boat to this project so I have a stable sail-powered boat to use with my family...

I live in very land-locked South Dakota, doing all of my sailing on tiny lakes in SD and MN, where the vast majority of other boaters are puttering around on aluminum pontoon boats. I too enjoy this same sort of puttering around, I would just prefer to do it under sail power. The lakes I sail at most of the time are 3-5 miles wide at most, so there is no where to go fast to anyways. There are a few bigger lakes/reservoirs in SD that I've been sail camping at a few times with my Prindle, but I can't take my family with my current setup. I'd like to be able to bring them along, even if it meant slower sailing and less distance covered.

Someday I dream of a more elegant boat, maybe when I'm done with school and we have a second income to keep our budget afloat. But for now, I'm still kind of intrigued by this possibility.

With these parameters in mind, do you think this is this still a dead-end proposal? Or, with maybe a few expert tips, are there some ways I could make this work out at least a little better. Maybe just the slightest bit faster or easier to control... Thoughts? And I'm certainly not opposed to just tossing the idea. This sort of discussion is why I have brought the idea to the forum. Thank you!

 

I think it would be a waste of time and effort, even if none of the hardware costs you a thing (which is likely not true). Keep the trailer, remove any usable hardware and deliver the hull to a land fill. The trailer is worth a fair bit by itself, check how much trailers without boats are worth on craig's list.

You might consider using your extra Prindle hulls to make a trimaran, it is actually a great idea. it would not cost too much to make a plywood stitch and glue hull that is simple, but much more suited to the purpose. Keep it simple, it would not cost much more than what you are planning now, and you would get something much better and still meet your goal of a comfortable day sailor for the family.

 

Biggest problem with the Crestliner hull is the weight, not just the shape. It is very inefficiently designed to do 40+ kts, so weighs far more than the Prindle rig could safely drive, as the righting moment will exceed the rigs structural limits.

 

Also being fundamentally broke, I understand your wish to do what you can with what you have. Unfortunately, the other guys are right - that speedboat hull will be a very poor choice to build any kind of sailboat.

Silly suggestion - why not just add some stringers and a simple plywood deck between the Prindle hulls and build a small lightweight cuddy onto it? That way, you have sailboat plus some comfort and cover from the weather - adequate for overnighting. Just keep the weight down and although not exciting, it will at least sail. Also, no messing with the rig or rudders

 

https://c2.staticflickr.com/4/3016/3009804503_c15bb22206.jpg

plus

http://robborruso.com/Sailing/web_site_pics/IMG_0029.JPG


pogo

 

The power boat hull is just a bad idea like others said.
If you want some more room on the prindle for kids, think about adding a tramp fwd of the front crossbeam. Don't go out to the bridle with it so it will not contribute to a nose dive. Find a piece of old aluminum mast to support the front end. There have been other boats that did the same thing.

If you still want better stability and room, make up some seating benches like the old Hobie 18.

If you still want absolute stability, put in a reef in the main or remove the jib.

Deliver the Crestliner to the dump as has been suggested, sell the trailer to pay for the tramp and seating benches.

 

Thats a lovely old speedboat, buy an engine and enjoy! I'd love a boat like that.

 

Funny I can't see the pic of the trihull, but can see the catamaran !

 

You can build a very crude but efficient wood hull in maybe two weekends out of say 7 sheets of plywood and a few 2x4s and maybe $100 in expoxy that would sail a lot better than that power boat. It'll be less work than trying to convert the powerboat, sail pretty darn well, and probably even cost a bit less. I'd be happy to draw a very quick and dirty set of plans that would only be for rough example if you're interested.

Good luck with whatever you choose.

 

Yes, I would say you'd be best to convert the Prindle to a family cruiser like the Hobie 21 SC (Sport Cruiser)

Forward trampoline, Wing seats, and mini cargo pod thingy across front of trampoline.

https://www.youtube.com/watch?v=VIqAhV_ZEHA

 

building a simple hull is actually not the costly part of a boat, the rigging, fittings, sails, rudders, etc. etc. are actually the larger part of the cost. If I had the spar parts like you, and a whole rig that is suitable for both a fast beach cat and can be used on a comfortable cabin trimaran, I would seriously consdier building a purpose designed center hull with a cabin, it can likely be done for about $500-600 if you shop carefully.

Also consider that an unattractive kluged together power-boat-and-prindle Frankenstein boat will not endear your wife to sailing either.

It is very important to approach this issue carefully if you ever want your wife to share your interest in sailing. Most women like the IDEA and the romance of sailing: boats out on the water look so graceful and pretty gliding along when seen from shore. Building something and going out and challenging the elements is a pretty much a guy thing (I am almost certain most women would never want to handle goop, epoxy or sand fiberglass, or willingly sail with wind and spray in their face).

So you have to pick not just the boat, but also the time of year and conditions where it will be a very pleasant experiance for her. And once the baby has arrived, you NEVER want her to feel HER baby is ever in any danger. In many ways a cat or tri is much better than a monohull since it will not heel nearly as much, adding to the worry of a newbie.

So consider making a suitable center hull, with a comfortable (even if small) cabin to get out of the wind, with a roomy and comfortable passenger area, and if at all possible (even if you have nothing else in the cabin) a roomy and private place to use the toilet and change diapers.

Keep it clean and simple, and do not take them out on it until it is done, painted and looks pretty (no raw edges, or unfinished surfaces, keep rigging and gear stowed and neat, etc.). A boat with varnished wood, soft colors and atractive lines she would be happy to be in in and to be seen in. I think an ugly duckling Frankenstein boat she would be embarrassed if anyone she knows comes along and sees her in it. A nice looking boat (even if simple and inexpensive) she likely would be proud to invite her friends to come see and enjoy as well (presuming there is room in it for visiting friends). And than as your final plan of actions, ONLY pick warm sunny days with gentle breezes, to go out in. Surprice her with a real pick-nick basket full of a nice lunch or snacks of her favorite foods: strawberries dipped in chocolate, fancy cheese and a white wine, what ever she likes (remember too that for women, the presentation of the food is just as important as the taste, so use attractive serving bowls or containers as well, with bright and cheery napkins). Do this enough times, than all of her sailing experiences will be all full of happy memories of what a great and considerat guy you are, and what a great boat builder and sailor you are as well.

Eventually she might actually enjoy some larger windy days and doing fast reaches across the lake, or even overnight boat camping in it too. But do not rush it. And most importantly, consider her experiance and her fears and likes about being on the water. If you do not, you will never get her (or allow your child) to go out on a boat with you again, and t could lead to a very costly and bitter divorce.

 

Petros has hit the nail on the head, and the day she says "can this thing go a bit faster" you know you've won!!

Make sure the prindle can still be sailed as a prindle as well, as in a blink of an eye (a couple of years) the little one will be screaming with pleasure out on trapeze.