It sounds like they are just surface cracks which do occur at the transom since that area takes a lot of load, gelcoat is not very forgiving and goes not flex well and cracks. I agree I would still have the boat surveyed regardless, that way you know it is not something more below the surface, or a repair resurfacing, but it is likely it is nothing, but spending a few bucks now to know is better then finding out in a year or two and having major work needed. I would though highly recommend taking care of those cracks to prevent them from expanding, because they will and down the road a few years from now could become the cause of issues. You can get the gelcoat repair kit from a Grady dealer to match your years gelcoat. Drill out the 2 ends with a drill in reverse,.....always drill through gelcoat in reverse or you will chip it badly. The drilled ends relieve the stress and will stop the crack as long as the drilled hole is slightly larger then the actual crack itself, the hole and crack is then repaired and covered with the new gelcoat and if done neatly will be very hard to notice, and likely only you will know its there because you did the work, anyone else will have a tough time ever realizing it.
