Omega Seamaster

[pellegrino]

Hi

I have had my watch now for sometime, it's an Omega Seamaster Professional Chronometer (300m/1000ft) with the sweeping second hand. But can't find the instruction booklet.
My question is that it has a rotating bezel on the out side (only rotates clockwise), and I was wondering what it's for and how to use it.

Also the usage of the screw down valve on the top left of the watch?

Does anyone have any idea or can advise me as I am just about to take my PADI diving course.

Many thanks

P.S. Here is a picture of it if it helps:

http://www.rolexreferencepage.com/seamaster/bo ndreview.html

Thanks again.

[kempie]

Have you not read the article to which you link?

"Encircling the dial is a unidirectional rotating bezel - a common feature on dive watch used to track the remaining time on a diver's air supply. Another feature of this watch which helps it earn "Professional" designation is the helium escape valve located in the upper portion of the case. Deep sea divers use helium mixed with oxygen in the air supply. After spending time at extreme depths, divers must spend time in a decompression chamber before returning to normal sea level conditions. While in the decompression chamber, the helium in the air can actually permeate the seals of a watch, and pressure can build inside the watch case. The resulting pressure build up can actually blow a watches crystal right out of the case. To avoid this from happing, divers can manually unscrew the helium escape valve on their Seamaster which gives the helium a way out of the case."

Are you sure the unidirectional bezel moves clockwise rather than anticlockwise?

Align the bezel pointer with the minute hand at the start of your dive, then you can tell at a glance how much time is left before having to ascend e.g. if your dive plan is 30 minutes you will know this time has elapsed when the minute hand is on the 30 marker.

The safety feature of the bezel being unidirectional is if the bezel gets bumped hard enough to rotate, it will show a longer elapsed time, causing the diver to automatically err on the side of caution. By believing time is up and ascending earlier, they will avoid being fooled into staying down too long thinking they still had plenty of time left.

[pellegrino]

Wow, that's great - thanks so much.
And yes, i did mean to write anticlockwise and not clockwise.
I will also look at the article closer tonight too!!

Thanks

[charlieboys1]

I�m advanced Padi diver and I�ve had this watch for about five years now and its been on several dives with me my deepest was in Egypt 50mtrs it�s a great watch the info you want: A bezel is a rotating dial on the face of your dive watch with a pointer indicator. When you are ready to descend, you align the bezel with the minute hand, where it stays for the duration of the dive. By comparing the bezel and the minute hand you can easily see how long you have been submerged. Note about the rotating bezel on a good dive watch: it will only turn counterclockwise! Since it is possible to knock your watch against your body or have it turn by accident. As for the screw on the left-hand side this is for Helium escape valve why helium escape valve? Air cannot be used for deep-sea dives, since nitrogen (a constituent element of air) becomes toxic at a depth of 60 metres.Therefore, when carrying out work at great depths, professional divers stay in a diving bell for several days breathing a mixture of gases containing a high proportion of helium. The pressure is gradually increased to reach the pressure at the working depth. The divers, still inside the bell, are then lowered to the working site. They leave the bell to carry out their work. Once their work is complete, they re-enter the bell, which is then raised to the surface. Pressure is then returned to atmospheric levels and this is when the valve must be opened (only for deep-sea dives lasting several days). You can download a instruction manual at the omega website www.omegawatches.com hope this helps