I have a lowepro dryzone. I took it to Kauai to hold my canon dslr and 3 lenses. The bottom is totally waterproof (submersible) and padded. The top holds other gear that can get wet. I carried it onto the plane and it fit well in the overheads.
I haven't used it since that trip in 2008. It's in pretty darn good condition. Been in a storage bin in the garage. I think it's missing a bungie cord that cinches down a section in the back but certainly not needed. All the pads are there and I'm certain I have the lube that you put on the teeth of the zipper.
I've been considering selling it recently and would be happy to entertain and offer.
I just don't use it any longer as I use a waterproof camera when I go fishing.
PM me and make me in an offer, I'll send you photos if you need em.
Lowepro - DryZone Rover
You should be able to find these used on e bay for less than $329