Not sure actually if U have the hard spot or not - it may just be where the light is striking in the photo - this website reduces the resolution so much its hard to see close details. Its not a major concern, mine only reveals the flaw when sunlight is shining directly downwards - & its probably only visible out of the water, from ground level. Its not something I'm worried about - I think I've heard that it occurred during the original hull layup, if the fiberglass was taken out of the mold too soon, before it fully cured & hardened. I know some Catalinas also show wear through of fiberglass cloth in spots of wear, etc. More of an aesthetic defect then a structural concern. Hope I didn't worry U uneccessarilly. I'm not loosing sleep over it, but I've seen this more than once, just like the Catalina smile, it is what it is.