Originally posted by DJL
The question is how serious a problem is this likely to be?
Without close examination by an expert all is speculation.
Most likely as others suggested is a gel coat crack but also you mentioned bubbles so it may be more serious than that.
However, the question is how long has been there?? If it has been for a long time you might find (this is the worst case) that the ply under the jell coat is rotten or damaged and may need repairing.
Is all very easy to be repaired by an expert ONLY!!
But you should take it up with the manufacturers before you do anything else.