Hello Jim,

It is definately possible if the boat was left filled with water- or partially filled. Usually water infiltration will result in the glass "weeping" when hauled out, or in your case just when drained. Let it sit upside-down so the part where the water infiltrated is pointing down, and after drying it out see if water weeps out of the glass. Also with bad water infiltration there will be a "mushiness" to the fiberglass.

If you do have infiltration you can drill pinholes to help the water get out and then coat it with epoxy. Really with a layup as thin as a kayak you can probably just dry it out over time and not worry too much about it.