You can buy waterproof boxes (sorry, no links) that will hold some keys, a few ciggies, and some money that you can strap on a limb or around your neck. Better than shoving them in the exhaust pipe or in the wheel arch and coming back to an empty parking space.
Most wetsuits have key pockets under the armpit. Find a sympathetic publican to leave an electric key with, or wrap it first then put it in your wetsuit. I think you can still buy manual keys for cars as well. Oh, and do some pressups first!
ah ok thanks guys, my spare car key is manual so I'm inclined to leave the electric one at home and take the manual one in a pouch into the water maybe. I'll probably still panic about it escaping and floating off though!
various beaches along the north coast of NI, just whichever takes my fancy and is quietest of brats from the city...have never seen a lifeguard hut on any of them before, they seem to just cruise about in pickup trucks. except possibly benone where there's a tourist centre thingy but it's probably the one I will be going to least tbh.