Bezel on a Dive Watch

Get Underwater

Gear Info

Destinations

Travel Info

Misc

Stay in Touch

Site Info

[?] Subscribe To This Site

Bezel on a Dive Watch

Hello, I have always been curious about the fact that dive watch bezels have distinct markings for 0 - 15 minutes; what is the significance of the first 15mins in scuba diving, a reason enough for all dive watch manufacturers to consider in their watch designs?

Will appreciate your insight.
Many thanks,
john-john

Hi John-John,

Good question. Never thought about that before but, unfortunately, I do not have an answer for your question. I did some research on the internet and couldn't find a suitable answer either. I found some guesses but none that made sense to me (i.e., to let you know you have to come up after 15 minutes ; why would that be? dives don't last 15 minutes).

There is no significance for the first 15 minutes in scuba diving - at least not in recreational diving; I can't speak for technical diving since I am not certified for that.

You have me curious now. I will try and find some more information. I'll let you know if I find anything.

Can anyone else help us out here? All thoughts would be appreciated.

Dianne

Comments for
Bezel on a Dive Watch

Average Rating

Click here to add your own comments

Rating

Bezel on Dive Watch
by: monsen

Bezel markings
Most contemporary dive watches with conspicuous 15 or 20 minute markings on their bezels, are the result of copying a Rolex bezel design of the 1950s. Back then divers typically planned a dive to a certain maximum depth based on now obsolete US Navy dive tables, and dove according to the planned dive profile. If the dive profile allowed a bottom time of 35 minutes the diver, upon entering the water, would set the marker on the bezel, 35 minutes ahead of the minute hand. The diver calculated this with the 60 - bottom time formulae (60 - 35 = 25, for 35 minutes bottom time the diver would align the 25 minute bezel-mark with the minute hand). Once the minute hand reached the main-marker on the bezel the diver would begin his ascent to the surface. The 15 or 20 minute scale helped with timing the ascent and whatever safety stop the diver deemed necessary. For contemporary diving methods the 15 or 20 minute "count-down" bezel is quite antiquated.[13]

more info on dive watches:

http://en.wikipedia.org/wiki/Diving_watch#Crown

Rating

Possible Reason for Dive Watch Bezel
by: Anonymous

I too have searched the internet, and too, in vain for a suitable answer.

I'm a recreational diver, myself. To share with you further, I have noticed in resorts that intro dives (for non-certified divers) last about 15 to 20 mins; aside from the safety issue of leaving enough air in the bottle for beginners, perhaps it may have something to do with the saturation of
nitrogen into blood over the 15min period of time?

Perhaps less than 15mins then nitrogen saturation is negligible? Then again, I know that is reaching hard for an answer because the nitrogen
saturation is a function of both time elapsed AND pressure. Sigh.

Will appreciate any insight you come across. I, too, will let you know if I find the answer.

Click here to add your own comments

Join in and write your own page! It's easy to do. How?
Simply click here to return to Information on Scuba Diving

footer for Scuba diving page

Bezel on a Dive Watch

Comments for Bezel on a Dive Watch

Comments for
Bezel on a Dive Watch