We want to tow on our current boat trailer between the Hobie's hulls. So I made some adapter/holders for it.
The first step was to measure out the Hobie trailer, specifically the relative positions of the three cross-members that would have the holders bolted to them. After I had those measurements, I determined the position the Laser would have under the Hobie and made wire-profiles of the Laser's hull at the points of the cross-members.
I started with some stiff wire and laid it on the Laser's hull at the position I wanted a profile. Then I bent and rebent and rerebent (etc) until they matched the profile. The next step was to transfer these to some cardboard.
These are then transferred to some pressure-treated 2x10's and cut out. They are only half profiles because I found that it was easier to mark half and flip them over to do the other half than to have a full carboard profile; doing it this way also more-or-less guaranteed symmetry (the wire profiles were far from perfect).
My setup. The jig-saw was used to cut the curve. The circular saw was for relief cuts. Wasp spray was for wasps.
In retrospect, a jigsaw is not the right tool for this. They just aren't meant to cut anything over an inch thick. It was incredibly frustrating and slow, and I broke three blades on this project. Unfortunately, we didn't have any other tool that could cut curves. Here's the result after much sanding:
Profiles in order from left to right = aft to fore. Spacing not to scale.
Unfortunately, the wire must have bent slightly inward from handling, and they all ended up not fitting right. I had to go back with the jigsaw and widen up the curves.
The next step was to attach carpeting to protect the boat's hull. I cut up an old weather-proof rug into strips and shaped/stapled/nailed the fabric to the holders. Here's the final result:
The next step is to bring them to the trailer, mark/drill holes, and bolt them to the trailer. Due to weather, I haven't been able to do this.