Hull Repair GP14

I don't know how ( I suspect that I caught the hull on the launching trolley)  but last time I took my GP14 out I managed to put a hole in the bottom. The hole opens out into the starboard bouyancy chamber. I have fibreglassed the outside and assume that now to give it the necessary strength I will have to break into the bouyancy chamber and complete the repair from the inside, and then reseal the bouyancy chamber. I would be grateful for any tips/advice regarding this procedure.

A better way (if you undo all the work you've done already) is to open out the hole big enough to fit a glass patch through (if a flat panel, you can make it on a board, then cut it to shape) which you the bond in place, much as you would a piece of ply on a wooden boat. You can then build up your repair on that from the outside.