Patching gelcoat is a simple repair, buy a tube or bottle of gelcoat patch at West marine and apply. Fill and wet sand a second time, then compund and polish.
The challenge is getting a good color match which is very difficult for the DIYer to do. You can practice with the color tints to try to find your own match, good luck with that, or you can pay a professional to get it reasonably right. If you don't want an off-color circle on the hull for the remainderr of your ownership experience, hire a pro.
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