That the watch I use as my dive computer is a Garmin MK1 Descent which is rated at 100m and my sea dweller is rated 1200m. I'm a recreational diver and I have the basic PADI certification which allows you to go down to ~20m. If/when I want to go see something deeper, I'll get the certification that gets you down to ~40m. Beyond that, you enter the realm of technical diving and unless there is something really beautiful that I must see, I don't intend to do this. The deeper you go, the more air you use, and you need to incorporate decompression stops, all of which shortens your dive time. In addition, the danger increases quickly with depth. I dive to relax, in general on vacation. So recreational diving is in the 0-40m range and if a reputable watch manufacturer reports a rating of 100m, and it has been checked (and its gaskets are ok), you are good to go in the pool.