Bolts (threads,nuts) or screws that just go into fiberglas? If your deck is cored with balsa you will need to pot the holes with thickened epoxy. There should be an excellent post here on how to do all of this by MaineSail, might be a sticky in maintenance. Do a search, should be able to find it.
SV Laurie Anne
1988 Brewer 40 Pilothouse