Might be worth having a look at this site.It looks like its only the gell coat thats damaged. You would grind it back to sound gellcoat and then fill with the same, sand and polish.
The hard part is getting a good colour match, that's where you would benefit from a pro doing the job.
That's what I'd do.. or use white extra fine Milliput putty - amazing stuff..As already said, fixing the hole is simple, the next question is how closely do you want to match the colour. Simplest is to get plastic padding white gel coat repair, put a splodge of unmixed on the hull and see if the match is good enough. If the boat is relatively recent you could as the manufacturer/ dealer if they have matched filler, or if not what the colour code is, then speak to someone like East Coast Fibreglass Supplies who will sell you the tinted filler. Failing that , get a professional to fix it and ask them to supply you with some of the filler for future use.
Or... you could just leave it, it's only cosmetic