Omega, I really like these:
http://www.aquapac.net/

I've posted about them before, but it seems like no other forumites share my enthusiasm.. fwiw. I have several, and have never had a puncture or other failure. The one I use most is around 1.75 to 2 x larger than the Ritter PSP and hangs either on it's lanyard around my neck (safety lanyard) or on a belt with the integral belt loop. Everything is in it except a small neck knife (HAK knife) which is ON the lanyard. Although I usually have more emergency gear with me... this is my "last ditch" kit.

I evolved to this mode of carry after a near-tragedy of my own making on the water. I got snagged in the water and had to ditch my boots, pants (and the PSP, etc. in the pants pockets and on the belt). Couldn't save the kit and save my A** at the same time. MY BAD. However, from that point forward whenever I'm on the water the Aquapac is on my neck. Certainly, I could end up having to ditch that too - but I think I'd have a better change of saving it. I'll wear it IN the water, too: under a t-shirt, next to my skin. Looks a bit goofy (but I bet most of us ETS'ers get used to that observation from non-believers).

Anyway, I'd love to hear from others: What am I missing...why aren't there more Aquapac fans here??