How do I fix this? The cracking is in my battery compartment. It's there because the !@$@%^&*! idiot that owned the boat before me thought it would be a good idea to drill drain holes in the bottom of the battery boxes.

There's no evidence of the cracks going anywhere up the transom. The second pic is looking back towards the transom. The cracks stop there. Stringers look good. Nothing seems to be soft. I think I just need to seal this up to prevent further damage.

Looking for your ideas on this...

Looking down from top...

Looking back towards transom...

There is a gentleman on here that knows his stuff when it comes to fiberglass he would be able to help you. The only thing is I can not remember his name so, I would re post this with a title that says something like " cracked fiberglass help" or something like that and you may get his attention. Hope this helps!

You might be able to remedy that with some fiberglass resin and fiberglass sheets available at any auto supply store.

There is a gentleman on here that knows his stuff when it comes to fiberglass he would be able to help you. The only thing is I can not remember his name so, I would re post this with a title that says something like " cracked fiberglass help" or something like that and you may get his attention. Hope this helps!

I think you might be talking about Tom "Fishing Rhino".  I have already sent him a pm with a link to this post.

I'll change the name of the post... good idea.

I think you are right, he is the guy who did race cars. Good luck!

As long as there is no structural damage, fiberglass cloth and resin over the entire cracked area. I'd go up the sides a few inches as well.

Apply resin, then the cloth. Smooth it out. Apply a few more coats of resin. You should be good to go. Home Depot sells fiberglass cloth and resin.

Chances are that is the gelcoat cracking. The shelf is either made of plywood or glass. All opinions posted will work.  Work in the industry and if you have any questions send me a pm. It's easy, if you know what your doin.

grind off the gelcoat before doing repair. use vinylester resin or west system epoxy. 1 layer of mat then 1 layer of 1808 will be more than enough then re gel.