EMP,

You sound like someone who likes to research things themselves. So here's a link to get you started and you can check all the sub documents from there.

http://www.uscg.mil/hq/cg5/cg5214/survivalequip.asp

Scroll down about 2/3 of the page to see the emergency water overview.

Note the details about seem sealing, drop testing, tumble testing, temperature and more.

Hope this helps and good luck in your research.