good light rowing dinghy plans?
 

Does anyone know of any good plans to build a solid but lightweight rowing/sailing dinghy? Ideally I'd like to build it out of something light like divinicel and fiberglass (sandwich). Something about 8ft should do the trick. The idea is to haul it up on deck when sailing so I'd like something light. Has anyone built one they could recommend? Has anyone tried building one using a foam/fiberglass sandwich technique? Thanks in advance!

I think a stitch and glue marine plywood design in that size range would be lighter than a foam cored GRP dinghy. Check out the CLC line of designs.

I thought a foam core would be lighter than ply, but thanks for the suggestion.

In larger sizes, yes, but the smallest boats are often lighter in stitch-and-glue than in GRP. A stitch-and-glue boat doesn't even need to have a full coat of fiberglass on it, where the skins on the foam-cored GRP boat have to have a minimum thickness to guarantee the core's integrity and provide sufficient stiffness to the design. Marine plywood, even 1/8" is pretty stiff torsionally, unlike foam, once it is bent and held in that position.

For instance, the Chesapeake Light Craft's Eastport Pram is 7' 9" x 48" and only weighs 62 lbs. One 8' GRP/Foam dinghy that I found on the net weighed in at 130 lbs... People often underestimate how much epoxy or vinylester resin and fiberglass cloth actually weigh.

I'm planning the same thing but I want to stick to all composite so my plan is a fiberglass and carbon fiber dink with vinyalester resin. I'm shooting to keep the weight under 40 lbs. I happen to have a 7 foot pram mold but if I didn't I would build a quick and dirty pram mold using masonite with a little stitch and glue technique. There are plans out there if your not up to designing one yourself. I still plan to use my inflatable but this one will be designed with a removable seat so it can act as a cover for the rolled up inflatable. I never tow the dink so this one is just in case I need to kedge out an anchor or make a quick trip to shore and not bother blowing up the inflatable.

Tooting my own horn:

http://i27.photobucket.com/albums/c1...kend0293-1.jpg

Hard dinghy, low-buck style

Have a look at the designs from B&B, Graham has drawn some very sweet boats… I built a nesting Spindrift, really nice little boat that rows beautifully. If you built one from a material called Coosa, it could come in at a fairly light weight. I’ve never used that material, but have heard great things about it…

spindrift

Now, if you want to go ultra-light, have a look at Platt Monfort’s boats, they’re very cool… Whether they would stand up to the rigors of use as a yacht tender, of course, is another matter…

Geodesic AiroLITE Boats - ultra lightweight SOF canoes and boats; plans, projects and tutorials

Please be aware there are BIG differences in rowing boats compared to trade offs like flat bottom skiffs that row like a brick.

Like Denise said. The Nutshell dinghy from Woodenboat is supposed to row and sail well. They have a number of other designs that might do what you need - including a Whitehall, but that's another thing entirely. Chesapeake Light Craft is expanding beyond kayaks too, and might be worth a look. One caveat: I've heard that if you go too light in a boat designed to be capable of carrying a load (not a single scull, for example), the boat doesn't carry well between strokes. There's simply not enough inertia to maintain speed.

I have a Spindrift 10N (N for nesting). I like it a lot. It's definitely light enough, especially once split into the two halves.

My only complaints are:
Low freeboard. Could another 3-4" there.

Low Boom for the sailing kit. The little boat has a huge sail for it's size, but the boom is a bit low for operating while sitting on the seat. Sitting on the bottom, you tend to get a wet bum (see freeboard issue). I planning on having the boom raised (shortening sail) a bit to make it more manageable. I don't race so I don't really care about top speed.

The spindrift does row and sail very well.