Re: Water to 30 meters, but what about SALT water??
30m is not a hardcore diving depth, PADI Advanced diver goes to 30m (and it's not that advanced really, no gas mixes, no rescue techniques,BSAC in comparison covers some of this stuff at their basic level), a lot of people on holiday will do that in addition to getting their basic OW (open water diver). BSAC basic OW goes to 20m.
Give you some idea, couple of popular wreck sites, Scapa flow the wreck depths are about 25-50m down, and Truk Lagoon is around the same. At that point you probably want to be a bit experienced as a diving past 30m (varies depending on the school) because of things like nitrogen narcosis and the bends get more risky, you probably start wanting to look at gas mixes.
The hardcore divers are either the pros who do it for a living and work at some really really deep depths, or technical divers who seem to like pushing limits on how deep they can go (and it gets super geeky with all the prep etc), think the deepest so far recreational diving is about 330m and it took almost nine hours to ascend from that depth.
Jumping in can add pressure to the watch, likewise swimming and so have an effect on water resitant watch depth ratings. From what I understand resistant is it will hold be ok at a presssure rating it says but prolonged exposure gives a chance of water ingress, waterproof it will be waterproof for full exposure at the pressure rating.
I wouldn't buy a dive watch rated for less than 100m waterproof, and usually there are not many that are less than that touted as dive watches. Dive watches are rated at ISO 6425. Which is a bit more thorough in testing. I think you also get issues with things like gas epxpansion, thermal shock etc. I have had a perfectly good brand new watch have all the screws bar one on the bezel come out on a dive, only thing I can think of may have been one of these issues as they were all tight when I started the dive.
Biting the hand that feeds IT
