I own an O'Day Mariner that has the same problem only worse. On my boat there is actually a hole the size of a nickel where the forward edge of the CB case meets the hull.
I have done quite a bit of research and asked questions at other forums and here is what I am planning to do for my repair.
Remove the compromised fiberglass until I get to good solid material. Then I'll grind out a tapered area about 3 to 4 inches in diameter (taper will be deepest at hole and feather out 3 to 4 inches from there), and finally, I'll apply layers of fiberglass cloth and epoxy until the area is built up to match the hull. I actually plan to do this on the outside of the hull and inside the bilge.
If you do a search on "Don Casey" + "Fiberglass sailboat repair" you should get some good information. Mr. Casey has written several books on sailboat maintenance and fiberglass repair. West Systems also has information on their web site about fiberglass repair and offers a low-cost manual (less than $5.00) with sorts of examples and guidance on repairs. West Systems web site is
www.westsystem.com
Good luck, I hope your repairs are not extensive as mine.
Dan