Re: Cracked/Chipped gelcoat help
I have never really found a way to get rid of the Barnicle rings aside from sanding them off.
It never should have been allowed to get that bad on a bare bottom..but..it happens I guess.
As far as your repair..its just a Gel paste fill/sand/buff .. no need to get resin and cabosil.
What is your year/make/model .. I can probably get you the code ( you can call up Spectrum to find out yourself if you wish do double check

).
YD.