I think the best idea would be to chase down a set of plans and build one as light as possible.

I built a small plywood dinghy (a Welsford Scraps) and converted it to be a nesting dinghy by doubling up the centre bulkhead and then cutting the planking between the two. My main motivation was to be able to fit the dinghy in to the back of the car so that I can store it at home. For that it works great - fits in the car nicely and takes about 3 minutes to assemble on the beach.

My second motivation was to be able to nest it on the foredeck of my 22ft boat. For this it's not so good. The design was not actually meant to nest, which means the two halves don't fit together too well. Its a bit heavier than I would like to have to haul on to the deck and it would be cumbersome to set up/take apart on deck or on the water.

My advice would be to avoid trying to nest a boat that wasn't designed for it :-)

If I were to do it again (and I may just do that!) I'd be looking at a Stasha skin on frame dinghy. Super light weight and nests well: www.woodenwidget.com/stasha2.htm

I appreciate the suggestions but I don't really want to build another dinghy. this glass one as I said is a little on the heavy side so I will have to use a halyard to hoist it but that weight can generate momentum when rowing. Also its bullet proof when pulling up over rocky beaches etc
More thinking needed perhaps.
George

It depends on the shape of your pram dinghy. From my experience, a dinghy to cut in half needs to have a bit of a V-shape to the hull, so that one half nests on top of the other, as though it is hugging it. If the sides are vertical, then that won't happen and the top half will be 6 inches or so above the bottom half. The other thing is that ideally you'd cut the dinghy about 60% to 2/3 of the length, so that one half rests inside the other, and they are not equal length, especially when you have a buoyancy chamber up front. To fit on a foredeck having halves of a square dinghy there is not as easy as a truncated triangular shape, i.e. I prefer to start with a dinghy that has a narrower pointy bow and narrowing transom.














The first photo of Nick is what I built, by narrowing the transom of a Spindrift 9N I think. The big guy and his little nesting boat is from somewhere online, I forget where. And this last photo is a normal Spindrift 9N I think. Having the transom part so wide aids buoyancy, but is hard to walk around and manouvre on deck when you need to anchor, hence narrowing the transom. You can always add buoyancy by lining the inside hull with 50mm closed-cell mattress if you find the right glue. Usually joining the halves is by 5 wingnuts and bolts. You can add some foam around the bolts to stop water ingress.