Had a family emergency and didn't get to read the flotation thread until now. Some interesting ideas. A couple of things that weren't mentioned that really increase flotation:

1- put your front bulkhead as close to your feet as possible and your rear bulkhead as close to the back of the seat as possible. This will limit the volume of water allowed into the cockpit in a capsize plus it will give a larger air space inside the water tight compartments.

2- the use of a sea sock will do the same thing. Plus when you reenter with a sea sock most of the water is displaced and pumping out the cockpit is minimized or eliminated. Some people fear the sea sock getting tangled in their legs when wet exiting. This can be eliminated by using a simple system ( D-rings and clips) to attach the sea sock inside the kayak.

Just a couple of thoughts, Ian