Blisters can be a common problem with boats that are left in the water. Not just a Baja problem.

I would have someone familiar with marine fiberlass/gel look at them and if they are not too bad or not too numerous, just enjoy the boat and forget about them.

Blisters can form on any boat for sure. Some brands have resins that are more expensive, and much better to water resistance. The quality of the layup process itself can be important in preventing penetration. But since the gel coat is porous, some water will find it's way in.

Over time, water penetration can occur. It might not be too bad, so watch the blisters every so often to see if more form, or existing ones get larger. In the worst case, de-lamination can occur which is a major problem. I think it's quite rare that structural problems develop, but it's still best to have someone knowledgeable in these areas look at the hull, use a moisture meter, checks the hull's structural integrity.