john,
i don't know the answer to your question about the hatch lip. i was thinking of doing the same thing w/ the sponsons, only a slight variation. i intend to use mini-cell foam in 3" square by the lenght of the cockpit. i was thinking it would add alot of stability for fishing. i plan to velcro them into place when needed, and then remove them when finished so as to not promote extra moisture in the boat which may lead to rot. i found a place that sells sheets of closed cell foam for $5.00 a 4x8 sheet or a whopping $2.00 for a 2x8 sheet. its in knox indiana, a bit of a drive for you i'm sure. i've got a greenland design hull and i'm not certain what adding sponsons will do for its performance. people who fish from yaks consider them a luxury.....any ideas as to what sponsons will do to my performance?
hitman...south bend indiana