Well, be careful using chlorine bleach, especially belowdecks or near any metal (corrosive). It's also only really effective on hard surfaces. Doesn't penetrate in substances like wood, and the mold can return. But it will kill mold on fiberglass, if that's the only affected material fine.
Distilled white vinegar kills 80% of mold strains and won't hurt your marine vinyl or carpeting. But it's also an acid, so again use caution around metal.
See, it's hard to get "tried and true" glib advice with marine mold remediation -- there are ifs ands and buts given all the different mold strains and various substances the spores grow in/on. You don't want to solve one problem by creating another.