HELP: hull stress cracking

[Bushwacker]

I'd be inclined to mark the ends of the crack with a permanent marker and then use the boat for awhile to see if the cracks grow. If they don't grow, I'd consider them just cosmetic. The V only needs to go down to the bottom of the crack and width doesn't need to be more than 2X the depth, which is probably the bottom of the gel coat. A Dremel tool would work, or you could just drag a sharpened V-shaped punch type can opener or file along the crack to open it up.