When you find the leak and it's small. Say, a seam in the dag board well let go and it's hard to get to. Put the same vacuum on suck and feed some epoxy into the crack. Go easy on the pressure, just like Jake said but in reverse. It will suck the epoxy into the seam and fix you up. I've done that on several Hobie 18's and 2 Hobie 20's and it works like a charm.

J