Ziplock bags over you camera is a recipe for getting your camera fried.

For those of you that are saying don't wear your pfd and just have it on your boat - next time you go out on the water. Capsize.

Your hat will be going in one direction, your glasses will be falling off, your water bottle will be coming out of your boat, and any cameras in ziplock bags will be toast.

Then tell me how long it takes you to get your PFD off your boat, put it on securely & tightly, and whether you still have a boat or a paddle afterwards.

Then consider that if you are accidentally capsizing in "flat water" or so, generally speaking either conditions and wind have picked up or a boat has thrown up a huge wake - and realize that if you accidentally capsize, you are going to be freaked out, panicked, and your boat & paddle will be drifting away unless you keep a hold of them... So at least multiply your time above by 1.5 because of the freakout factor. It is absolutely amazing how panicked people can get when they capsize in a kayak - even when they're wearing a life vest & they know how to swim & they're only in 4 feet of water. Which is another reason to practice wet exits.

As for life jackets being hot... it's a water sport. get wet, splash yourself. Invest in a nice low profile life vest. I use a kokatat sea02, which has an all mesh back. NOt much in the front, it's a hybrid life jacket with about 10 lbs of built in floatation which is more than enough to keep me floating, but also has a co2 tank attached to it that will inflate the vest to 22 lbs of floatation if I pull a toggle - it's also got a tube I can blow air into it to fill it up.

As for peeing - I agree, drink a lot of water, don't dehydrate yourself. Jump out of the boat if you have to pee & don't have a choice of getting out. Carry a paddle float, pump, & stirrup & know how to get back into your boat and be able to self rescue.

As for seats - I've got no problems sitting all day long in any of my kayaks. Wilderness systems have extremely nice seats in the tempest or tsunaumi, they're like barca loungers.

Camelbaks - I put one behind my seat. People also get little backpacks that piggyback onto the back of their pfd & hold a hydration bladder. You can also stick a camelbak on your front deck.