Now, if you could pull the dents out with a contraption like this:
- HullBatten.jpg (25.01 KiB) Viewed 15258 times
a batten across the low spot and a bolt to hold the hull in place, and then somehow glue a stiffener on the inside, something like this:
- Stringer.jpg (16.92 KiB) Viewed 15258 times
which would hold the hull in place and not let it snap back. That might give you a (nearly) flat and much stiffer hull, so fairing it would require less material.
On a DS1, this is easy enough do to, because you can work from both sides. On a DS2, it would involve cutting access holes. My thought would be that you could cut the access holes from the hull side in your case, the laminate is damaged anyway. If you cut something like an 8x8 access hole, you should be able to place two of these stringers on either side by reaching in. And you should be able to place bolts to pull the hull up to battens on the outside.
The stringers I would laminate on a work table. Two layers of cloth one narrower than the other as a base. Then something hollow like half of a paper towel roll. Bend over the edges or use some fillet material to make a rounded transition. Then cover with two layers of cloth, again one narrower than the other (to provide something like a soft transition - I didn't try to draw them separately). If you find this too flexible when it's done, add another layer of cloth over the hollow part.
Because the hull should basically be flat in those areas, laying up the stringers separately like this should work - depends on how well you can pull the hull back into a flat shape. Trying to laminate it in place would be much harder.
Then fit in place, glue with epoxy, and lightly wedge against the inner hull with foam until cured.
I'm suggesting a hollow shape so that these cannot retain water.
To fill the access holes, I would laminate a bit of a flat plate (3-4 layers of cloth) on a work table first and tapering the joints on both hull and plate glue that in. If the area is slightly hollow still after the repair, you'd have room to fit a final layer of glass over the repair from the outside.
Anyway, this gives you something to discuss and elaborate on.
If you are planning a full restore, the total effort to do something like this will be relatively small compared to fairing/painting and whatever else you need to do. But if you just want something serviceable on the water with limited effort, you might be better off with sourcing another hull.