Gelcoat repair is something a boat owner can tackle. It depends on the reason for the crazing. If in solid fiberglass, then the concern is probably minimal. If in a cored area, then maybe more problems might exist because the cracks can let water into the core material, which can be a problem if wood core. Sometimes crazing can come from a fastener and sometimes from gelcoat that is too thick (usually older boats). If they are from say under a stanchion (lifelines), then maybe the glass beneath is weak from torquing in normal use. To get rid of them you need to grind them out, fiberglass them up and finish them with a putty (making it smooth) and then you can spray the gelcoat on and do the finish work by wet sanding the gelcoat from 320 to 400 to 600 grit and then buff your work out with fiberglass rubbing compound. That's a quick lesson, but you can do it.