My previous boat had extensive stress cracking both sides of the bow, and the price had fallen to come into my price range. I got a local fibreglass specialist to check it out, and his advice was invaluable.
We bought the boat, contracted him to perform the repairs (externally was just cosmetic), but most importantly, to stiffen the interior moulding by the addition of foam stringers, which were glassed in using overlapping "tapered" glass cloth. The stiffening was therefore applied progressively, which was designed to prevent it repeating (it worked over then next 11.5 years!).
The two starting points for the stress crazing were stiff spots on the inside of the hull where a cross-brace had been glassed in. This had stopped the hull flexing at this point, and flexing both sides of the stiff spots had started the cracks there. Apparently gel coat is slightly less flexible than fibreglass.
Could I suggest that you check for stiff spots round the crazing area by tapping gently on the hull? The dull thud of a stiff spot is a real giveaway, and if this was the cause, can be cured relatively easily, by spreading the load via tapered patches.
Mike