Well, disclaimer, I'M NOT A PROFESSIONAL. BUT, I've repaired numerous deep gouges with JB weld two-part epoxy then painted over with Rustoleum. Many I've done nothing more than that. If it's in an area where it will need continued protection, add skid plate or fiberglass patch. Deep gouges on the inside of the hull, I don't even worry about covering paint, just the JB Weld.
Now you see it:
Now you don't: