Not trying to point out the obvious here, but I would thoroughly inspect the plywood behind that crack in the picture before you slap some glass on there and call it good. If there is significant amount of moisture there it could compromise the stability of your rig
. And, this is a very common place for these boats to leak. And, it looks like from the picture a repair
has taken place there before. Judging from the location of the damage you are about 16-20 from where the chain plate comes down into the cabin so you are probably fine. But, while you have time it would be worth checking out.