So if you go with the "1st/2nd/3rd line of gear" concept, would a utility vest worn under your flotation vest be considered 1st or 2nd line? I'm a firm believer in pocket carry for critical items.

On another related topic, I really like RailRiders VersaTac Ultra-Light Pants. The thigh pocket has inner organizers and closes with both velcro and buttons on top as well as having a zipper on the front so you can access while sitting. These pants can carry a lot of gear if necessary. The ultra light version is ripstop nylon that breathes well and I have no doubt I could swim in them if necessary. Belt loops are well built and easily take a 1.5" nylon belt.

For survival pants, I want full length legs rather than shorts even in a tropical cruise ship environment.