I bought a Minolta waterproof camera several years ago and it proved not to be waterproof on the 4th dive.

As far as watches go, if you need a battery change and don't send it in to the manufacturer where they change the seals also, then you may as well forget the waterproof protection, I found this out the hard way when I rusted and ruined the inner workings of my Tag from swimming in a pool.

A computer once beat me at chess, but it was no match for me at kick boxing.