After much research for a waterproof camera backpack, I have settled on buying the Lowepro Dryzone Rover which arrived TODAY!
Why this Backpack?
I find that this backpack is just the right size as a carry-on in an airplane. It has quite a roomy top compartment, which allow me to pack my underwater housing or strobe and also some of my clothes in my portable dry-bag so that they too don't get wet when I am between boat transfers from land to island or island to boat during my dive trips.
Waterproof Base Compartment
This backpack has a waterproof compartment at the base of the bag with ample space for my camera, strobe, macro lens, extra battery, SD cards, battery chargers and other accessories which don't play well with water, especially sea water. Most importantly, the zipper! It's waterproof – TIZIP water seal zipper, which, I must say is not easy to open and close. Need to put my muscles to work when unzipping and also when trying to zip shut! The manufacturer is quite thoughtful in this matter, they have provided strategically placed D-rings for leverage.