Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
Define expensive. I dive with a Citizen Eco Drive watch with a countdown function for deco. It's rated for 200m and cost $175. It's relatively inexpensive compared to the Tag Heuer I own.
I'm not sure a scuba tank would damage a Rolex much--it takes a pretty good beating. But you're right, taking it off is risky. I hung mine on the shower faucet at the gym once and left it there, never to see it again. If you do your diving in the tropics, as I do, you just leave it on. The thin wetsuit slides over it and you pull the cuff up when you need to see the time, just like you do with a shirt cuff. Of course, there is no utilitarian reason to wear an expensive watch anywhere; they are jewelry. Any cheap quartz keeps better time than the most expensive automatic watch....I'm trying to figure out why anyone would wish to dive with an expensive dive watch in the first place ? Watches are small...so easy to drop/lose/misplace....you're taking it on and off frequently whenever you put on/remove your wetsuit....can get lost on a crammed/gear-laden dive boat amongst the tons of other gear onboard....set it down in the wrong spot and someone's scuba tank can easily crush it..it can make you a target for crime. My 'cheapie' (less than $ 150) Poseidon dive watch is rated for 500 meters depth.
I send it in every 3 or 4 years for service and resealing. It cost me about a hunderd bucks but damn I love that watch.