: Heinz,
: Thanks so much for the explanation. I found it informative,
: especially as the Decomp bezel is a favourite of mine.
: I understand that you say the 40M marker is in red as this is the
: max depth before decompression.. but I wondered.. what about the
: other markings.. if you go by the bezel, it would suggest that
: at 60M you have c4mins without decomp, 9 mins at 50M and 12 mins
: at 45M.. is that right??

: Also, nothing to do with the bezel, just my interest in how diving
: works...

: You say 40m is max depth without decompressing.. so what happens if
: you accidentally go to 41m, or 42 etc... is it a definite 40M
: point.. or is it gradual.. i.e..if you go to 40.5m, will you
: need to decompress?

: Just wondered!

: Stewart
: - Heuerville

Hello Stewart,

Thanks for your question. The markers on the DECOMPRESSION BEZEL are correct as well as your interpretation. However, diving is a variable sport in that there are no definitive numbers. A lot of variables such as a diver's Cardiovascular system as well as the condition of the Lung and its capability to eliminate Nitrogen play an important role. No two people are alike. So these numbers are general guidelines and each diver has to determine his or her limits. So here a quote from the diving manual issued by the
National Council of Aquatics ; Quote : [ Bottom time is the total elapsed time between leaving the surface and starting the ascent - not just the time spent at maximum depth. It would rarely be possible to make a dive to 150 feet or more, accomplish any useful work there, and be ready to start up- all within 5 minutes. So attempting such deep dives on a "Non Decompression" basis is seldom advisable] Un quote.

So you can see why they say and mark the 40 meters as a "Safety Guide Mark" on the bezel. Besides most of the scenery such as reef formation and fish life is best seen more towards the surface. For this SCUBA diving is excellent but for deeper dives we should use specialized equipment for many reasons.