Gel coat

He may have put new gel coat on it to protect it, but it sounds like he didn't smooth it out first. If you decide to smooth it out yourself, you will need to gel coat it again. If it isn't overly rough, it shouldn't hurt to leave it as is. It shouldn't actually slow the boat any.

A rough hull can increase fuel consumption. Smooth it out with 50 grit sand paper. If there are any divots in the hull, you can make putty by mixing talcum powder with fiberglass resin and hardener. Sand out the putty after it hardens, wipe down with acetone, then re-coat with top coat following the provided directions. You can spray top coat, roll it on using a fine sponge roller, or brush it on (not recommended). Hardener must be used with top coat, so only mix what you can use in a short time. The more hardener you use, the faster it hardens. No big mystery with this, and it isn't hard to do. If you make a mistake, sand it down and do it again...no problem.