Re: Gheenoe stretch and widening
hmmm
how to do a tunnel'd hull for a 1 off stretched & widened Gheenoe......................... yeah, no idea.............
But won't that affect the interior of the hull, raising it even further into an are already short gunwale height boat. It will have little FREEBOARD, the amount of gunwale (height) that extends from the plane of the water to the top of the gunwale, often measured static (not underway) & underway)....
Or at least that's the way I understand it for boats that aren't built w/ an outer hull & an inner raised/supported deck (floor, like a typical runabout)..
i guess you mean the tunnel will make the now larger surface area boat hull, that in theory should draft shallower, TRACK better. Rather then get blown sideways & off course since it is so much further from the 'steering' at the rear to the bow, that will likely ride much higher w/out sufficiently distributed weight, also guessing that the new & improved Gheenoe will get a larger motor to push the larger boat....... The motor's & captain's weight will be much further from the center of buoyancy since the hulls been stretched......
I also suspect that Exterior CHINES, CHINE LOGS (but on your shaped hull, not really chine logs) or a KEEL are the 'outside stringers' you're referring to. Those would be a solution, but again as a 1 off, custom, stretched & widened GHEENOE: How many chines, how long & tall should they be & where are they located fore & aft along the hull's bottom?
I can only guess, but a 3/4+ length keel along the centerline of the hull bottom, from the transom forward, @1.5" tall and 3/4-1" wide, may be sufficient. If not, add 2 chines to either side of the hull halfway from the keel to the start of the rounded edge of the hull as it transitions from bottom to gunwale. From your mockup photo above, it looks like that might be about where the transom corners are now, 1/2way between the keel & the curved edge. Run them about 3/4+ the length of the hull along that 1/2way length, also starting at the transom. They should be PARALLEL to the keel..................... If there is any curvature of the hull bottom as it goes from mid-ship's to the stern, the keel should get 'taller' as the hull rises, so as to keep an even, flat, straight plane along the bottom edge of the keel...
Hey, ya know: keep an even keel.............
The keel alone, or the additional chines, would make the hull track better and drift less then w/ out them.....
If you epoxy them in place, small aluminum angles set along similar lines as described above, might be more robust & last longer then a polyester resin & glass wrapped wooden keel or chine. You have some skills w/ fiberglassing & fabrication, I suspect a V shaped keel molded in glass & resin wouldn't be to difficult for you to mold & fill w/ PB & adhere it to the hull, a slight keel, would be better then none.
But I've never stretched or widened a Gheenoe, let alone both. Nor attempted to fabricate a tunnel hull.... I think the tunnel would greatly over create the necessary chine/keel tracking effect I think you are attempting. And with no camber to the hull, where does the tunnel start & stop fore & aft? The tunnel might create a stiffer hull, which would probably be a nice add to the stretched & widened hull...... A slightly curved piece of plywood is significantly more rigid then a flat piece, particularly when it's a complex curve, like the contours generated by the hull's shape for my plywood boat. Which uses a keel & chine setup similar to what I've described above........
