[sleepyhead123]

Seiko's Pepsi is the best example. But I'm wondering why is it that the more bold color is so early in the "count." While I know it is variable how much time anyone can dive, I'm wondering why the "emergency" color is usually in the first minutes of the bezel. Wouldn't it make more sense to put it in the latter half (or at least everything after 10 or 15 minutes)? Can someone explain why the most bold and warning-like colors tend to be in the region that is of least concern?

 

[CM HUNTER]

Makes sense to me as-is. It puts emphasis on the safe amount of time. It makes sense to warn you BEFORE it's too late instead of afterwards. Warning you after you've become unconscious/drowned seems pretty senseless, lol. Think of it in terms of a gradual type of thing... for instance going from yellow for 1-5, orange 6-10, red 11-15. Does anything past 15 (in some cases 20) matter?

 

[sleepyhead123]

I guess, though I would still think the red should be later in the dive instead of sooner. Also, I've only gone a few times, but I seem to recall that our tanks were good for around 80 minutes, with the expectation that we would be down no more than 60 minutes at the most to be safe (if we get agitated or start huffing and puffing, lost, etc). Of course that can be extremely variable person to person. 15-20 minutes seems a reasonable place to change colors, though I don't see why it would make sense to see red when I'm safe and blue when I'm in trouble (red after 15-20 minutes and blue for the first 15-20). These watches tend to advertise as tool watches so I would assume this isn't just for diving at the resort, where you expect to only be down for 10 minutes.

 

[mjmurphy926]

I guess, though I would still think the red should be later in the dive instead of sooner. Also, I've only gone a few times, but I seem to recall that our tanks were good for around 80 minutes, with the expectation that we would be down no more than 60 minutes at the most to be safe (if we get agitated or start huffing and puffing, lost, etc).

I'm not a diver, but given this scenario, doesn't it then make sense to keep the red in the 0-15 or 20 min range? If you are down for 60 min, you are good and once you hit 61 min, you are in the red until the tank runs out, albeit the second time around the dial.

 

[Toronto_Time]

Your Prayers have been answered!!

https://www.watchuseek.com/f74/stowa-seatime-black-forest-1340658.html

 

[Memphis1]

1. all diver's bezels are backward, because everyone copy the submariner
2. it was only used back when diving computers didn't exist
3. it should take you 15mins to come up your dive
4. no one uses these nowadays
5. the blue and red is only to differentiate, not because it's emergency color

 

[captain_hx]

1. all diver's bezels are backward, because everyone copy the submariner

Not all work backward and the ones that do have a reason for it. You time your dive because your body can handle a certain amount of nitrogen (it dissolves in your body as you dive). If you accidentally tern the bezel backwards, your dive time (according to the timing bezel) will increase and there will be no risk for you to exceed the critical time (red part, 15-20min). If the bezel would accidentally move forward you would spend more time diving (the bezel will show less) thus take in more nitrogen by exceeding the critical time (15-20min) and risk decompression sickness.

2. it was only used back when diving computers didn't exist

vintage divers still use them and many recreational divers use them as a backup to their dive computer.

3. it should take you 15mins to come up your dive

according to NAUI dive tables 15minutes is the maximum permitted bottom time for a dive at a maximum depth of 33m (110ft) with 20minutes being the maximum dive time at the same depth but with a compulsory decompression stop at 5m (15ft) for 5 minutes.

4. no one uses these nowadays

i use my bezel when boiling eggs. 2 minutes after the water comes to a boil is enough for the perfect breakfast

 

[sleepyhead123]

1. all diver's bezels are backward, because everyone copy the submariner
2. it was only used back when diving computers didn't exist
3. it should take you 15mins to come up your dive
4. no one uses these nowadays
5. the blue and red is only to differentiate, not because it's emergency color

That's a funny response because when I first came here I commented that no divers (that dive for a living) where diver watches anymore and I got slammed by a bunch of people saying how much safer it was to dive with a dive watch and how they are so useful and blah blah blah and proving me wrong with pics of their diver at the resort at 2 meters of water . . .

Still, if you're going to use blue and red, you'd figure you would choose the red as the marker of danger and the blue as being fine.

Well, I was just wondering if there was a logic to it all. Seems like there isn't a good one.

 

[sriracha]

In the older days it was to time ascents with decompression stops.

 

[CM HUNTER]

That's a funny response because when I first came here I commented that no divers (that dive for a living) where diver watches anymore and I got slammed by a bunch of people saying how much safer it was to dive with a dive watch and how they are so useful and blah blah blah and proving me wrong with pics of their diver at the resort at 2 meters of water . . .

Still, if you're going to use blue and red, you'd figure you would choose the red as the marker of danger and the blue as being fine.

Well, I was just wondering if there was a logic to it all. Seems like there isn't a good one.

Pretty logical I think. Put the warning that you have no more than twenty minutes in the red. Again, after the red, you're already too late. A warning at that point is irrelevant as you're already in trouble. By any other logic, it's like putting a stop sign fifty feet beyond the dangerous intersection.

 

[frenco]

I was always curious to know the reason of the double color bezel, but none of the explanations above makes any sense.
Bottom time in recreational diving is usually a function of depth, so 15 or 20 minutes make non sense at all, since at 130ft 20' is well beyond decompression obligtions, while at 30ft you're just warming up.
And in decompression diving these figures make even less sense.
But also, the unidirectional bezel is questionable since when used to time decompression stops, an acidental rotation would shorten the stop...
Best would be a bezel that simply cannot rotate accidentally.

But there must be a real reason for the double color, so i do hope someone chimes in with a good explanation.
By the way, it's more and more popular, for divers, to dump the computer and use a timer (watch or digital) and a depth gauge, mentally calculating the deco obligation on the fly with simple mnemonic models. Check GUE and some other agencies' protocols.

 

[CM HUNTER]

I was always curious to know the reason of the double color bezel, but none of the explanations above makes any sense.
Bottom time in recreational diving is usually a function of depth, so 15 or 20 minutes make non sense at all, since at 130ft 20' is well beyond decompression obligtions, while at 30ft you're just warming up.
And in decompression diving these figures make even less sense.
But also, the unidirectional bezel is questionable since when used to time decompression stops, an acidental rotation would shorten the stop...
Best would be a bezel that simply cannot rotate accidentally.

But there must be a real reason for the double color, so i do hope someone chimes in with a good explanation.
By the way, it's more and more popular, for divers, to dump the computer and use a timer (watch or digital) and a depth gauge, mentally calculating the deco obligation on the fly with simple mnemonic models. Check GUE and some other agencies' protocols.

You're going well beyond the simple question of the post. The OP isn't questioning if 15 or 20 minutes makes sense. It was a question of why the red "danger" color is in the allotted safe time frame instead of after that time. Focusing on the actual posed question... Logic would dictate that making a warning after you're already in trouble isn't really worthwhile.

 

[frenco]

Or the red sector, where the markers mark the minutes and not the five minutes, is the deco timing area, and the red indicates the necessity for maximum attention

 

[mrallen13]

Frenco has a pretty good suggestion on why. Deep diving where you only have limited bottom time means that each minute is crucial and you don't want to go over. So, the red is less of an "emergency" indicator than a "pay close attention" indicator I assume. I personally prefer to have minute hash marks all around the bezel just to make it easier to quickly see how long you've been down as well.

To be honest though, the red is probably there simply because it looks cool - at least to me.

 

[CM HUNTER]

Frenco has a pretty good suggestion on why. Deep diving where you only have limited bottom time means that each minute is crucial and you don't want to go over. So, the red is less of an "emergency" indicator than a "pay close attention" indicator I assume. I personally prefer to have minute hash marks all around the bezel just to make it easier to quickly see how long you've been down as well.

To be honest though, the red is probably there simply because it looks cool - at least to me.

I think this is right as well. This is why in my first reply I said that the first 15 (or 20) minutes of a bezel should be looked at as a gradually increasing warning (like going from yellow to orange to red) or "pay close attention" indicator as you say.

 

[kelt]

A change of color of the bezel area has no technical meaning.

The diving tables were calculated for duration by 5 minutes increment for depth of 3m or 10ft increments.

To check the dive duration, with the bezel pip positioned over the start of dive, a mark every five minutes is sufficient, but when doing the decompression, the minutes marks are useful since stop duration are rounded up to the next minute, resulting in odd numbers and the last minute of a stop is being paced to move up to the next stop level.

 

[Taswell]

Sounds like lots of non-divers in the dive watch forum.
Lots of watches have no 15 or 20 minute sector but have full 60 minute marks.
The popular division comes from early Rolex bezels that have been copied by other non-diving manufacturers ever since.
BTW the red does not stand out underwater and below 10 metres it appears black.

Another thread touches on some of the misunderstood things brought up here ...
https://www.watchuseek.com/f74/shouldnt-dive-bezels-count-down-rather-then-up-1360897.html

 

[Thunderdaddy]

Sounds like lots of non-divers in the dive watch forum.
Lots of watches have no 15 or 20 minute sector but have full 60 minute marks.
The popular division comes from early Rolex bezels that have been copied by other non-diving manufacturers ever since.
BTW the red does not stand out underwater and below 10 metres it appears black.

Another thread touches on some of the misunderstood things brought up here ...
https://www.watchuseek.com/f74/shouldnt-dive-bezels-count-down-rather-then-up-1360897.html

Just to follow up in support of Taswell's comment & info, the markation of "critical time" is not limited to a specified color, such as warning red...

 

[DM71]

The Russians to it differently. The red is left for the last 20 minutes. I cannot tell you for sure why they use this configuration as no one was able to answer the question in the Russian forum. Meanwhile, a Russian member told me his grand father use to be a military diver and back then, they use to dive with two tanks and the last 20 minutes were the indication of your reserve left to surface. I don't know if that's the real reason behind it, but that's all I know.

 

[CCJ]

In the old days, diving off of tables, they used the bezel this way:
- Determine max bottom time allowed from the tables for your desired depth (say it's 35 mins max bottom time)
- Before leaving the surface, put 60 - max bottom time on the minute hand (ex: 60 -35 = 25, so turn bezel to put the 25 mark on the minute hand and commence dive)
- Setting the bezel in this way puts the triangle pip ahead of current time to indicate when you're max bottom time is up
- The red/yellow warning color gives you a quick visual reference as you approach your max time (if your minute hand is in the red, you're already over your max, ascend now!)
- Having minute-by-minute marks in this ascent range allows you to time stops precisely
Now when I dive I have a computer and I don't set my bezel in this way: I just put the triangle pip on the minute hand and use the bezel for elapsed time. Most divers don't use the old method anymore, but the design tradition continues with the traditional 1-15 markings.
Cheers!