# Dive With Query



## chrisiden (Mar 16, 2005)

Can anyone explain why many dive watches (like the Seiko SKX009) have the 0 to 20 section of the bezel in a different colour (generally red)?

Thankyou in advance


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## pg tips (May 16, 2003)

there are a few scubies on here who should know. I always assumed poss wrongly that it was a warning for your last 20 minutes of air?!?


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## jasonm (Nov 22, 2003)

Yeah PG your wrong









Unless your watch can be connected to your air tank ( like some computers)

Dont forget that no device in the world can tell you how many mins of air you have left, it will only give quantity remaining in the tank in BAR or PSI...

I think its a 'safe zone' timer, ie if you dive at a depth of 'x' meters then 20mins is the max time that you can be at that depth and not make a decompresion stop, ( Ive forgotten the tables ..bad me







)

A deco stop is allways recomended though regardless, ( 3mins at 5 Meters )


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## pg tips (May 16, 2003)

my other guess was that it looks pretty









Why would anyone want to put themselves in danger and risk drowning is beyond me, I'm happy to be a desk diver thanks!


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## mach 0.0013137 (Jan 10, 2005)

pg tips said:


> my other guess was that it looks pretty
> 
> 
> 
> ...


 I`m with you on that one Paul







waters OK for drinking, bathing/showering, looking at or even sometimes getting caught in when it rains but diving in














mind you I can`t swim which might explain my attitude


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## chrisiden (Mar 16, 2005)

I'm guessing that the 20 minutes refers to the maximum a diver can spend at 30m without having to do decompression stops.

I did PADI dive training several years ago, training for dives up to 30m.

(I never did spend much time at 30m as the air supply would run out too fast)

P.S. I can hardly swim either, but surprisingly this is of little importance once under the water)


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## jasonm (Nov 22, 2003)

> (I never did spend much time at 30m as the air supply would run out too fast


Yeah Im a greedy guts with my air too


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## mach 0.0013137 (Jan 10, 2005)

jasonm said:


> > (I never did spend much time at 30m as the air supply would run out too fast
> 
> 
> Yeah Im a greedy guts with my air too
> ...


Go on Jason admit it your addicted to the stuff


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## jasonm (Nov 22, 2003)

I guess so


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## Nalu (Nov 28, 2003)

USN dive table (in Imperial units) No-D limits are easy to remember:

40' - 200min

50' - 100min

60' - 60min

70' - 50min

80' - 40min

90' - 30min

100' - 25min

(Air of course)

Citizen and Seiko are fanatical about putting these limits on their serious dive watch straps - eliminates the memory factor.

Once past 100', bottom time gets very limited and accurate measurement even more critical (one minute either way can mean the difference between repetitive dive groups). Since bottom times are <20min, the one minute markers can be used to accurately measure deep BT's. As such, they don't serve as countdown timers as much as more accurate count-up timers.

The only other use I can think of is for planned dives: you set the pip at the planned length of the dive and have one minute increments to measure how far you go past the 'deadline'. Silly, that, I know, but it's the only other thing I can think of.

I use my minute markers for timing safety stops.


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## mach 0.0013137 (Jan 10, 2005)

As a Desk Top Diver I`d rather the bezels were reversed showing time remaining not time elapsed, it actually would be useful sometimes in my job. Also good for parking meters telling me how much time I have left







Then the red section would be great.."WARNING ONLY 15 MINUTES LEFT!!" help me to avoid a run in with the `Yellow Banded Nasties` sorry nice local government employes who are doing a fine job


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