http://www.norcalkayakanglers.com/in...p?topic=2759.0
Found this thread on nor call anglers,
I read through all of it, this guy tried x 30 closed foam made a mess, he concluded it needs to be added during the manufacturing process.
Mostly everyone concluded, stuffedd your kayak with pool noodles, put enough noodles that your kayak doesn't sink stern or bow first.