All I know is my last Prowler Kayak when I would launch for La Jolla would take on a lot of water. I mean at times there was more tha 5 gallons of water inside, pretty scary if you ask me. I was told it didn't leak before I bought. Word of warning for buying a used kayak. If the inside of the Kayak smells like moldy water don't buy it or leak test it before buying. Trust me is will help keep your peace of mind.
I like the inflatable devices that can go inside the kayaks and may pick one up. Make sure you have the Coast Guard on your speed dial, and have a waterproof case for your phone. There are also automatic notification devices that will alert the authorities in the event you fall in.
http://www.basspro.com/ACR-Electroni...duct/10212900/
A buddy of mine has one of these and it saved his life a few years ago down off Baja.