Question about cold water and using a computer.

[Ryanh1801]

OK have a quick question. In my open water class, they made a point to say that during cold water dives or strenuous dives you should go to the next time on your dive tables. Im planing on diving over the winter up here in a wet suit so im sure on some of the dives I will be a little cold. Is their a way to put this into the computer? Should I just use my tables and use the computer for backup? Or is it nothing to worry about to much and just use the computer? I have a Mares M2 computer. I could not find anything about it in the manual, but I might be reading over it(not the best instruction manual I have ever seen).

Thanks for any insight.

[Navy OnStar]

Good question. I'm not sure if my computer will get more conservative based on temp. I know I can put in personal changes for physical fitness and such and that would make it more conservative. I'll have to check my manual when I get home.
If it doesn't and you want to dive more conservative then just come up a few minutes early.

[adv_diver1]

Unless I am wrong, if you don't have a really sophisticated computer, I am pretty sure the computer will not adjust accordingly for the physiological portion of the equation. I would go with the Dive Tables and use the computer as backup and just stay within the limits of the tables no matter what. Better safe than sorry. I would not trust my life to a computer that is for sure.

[MSilvia]

I dive in the winter in New England, without a computer, and only worry about the extra conservatism if I'm diving beyond rec limits. I wouldn't lose any sleep over it if you're diving in Texas.

[cummings66]

I dive year round and don't adjust anything for cold temps. I know I was told in class you should but in practice I have yet to find somebody who does modify. I am pretty sure my dive computer doesn't modify the times based on cold.

[wheelman]

You might check to see if you can set a personal adjustment on the computer to make it more conservative. That's what I do. Otherwise, use the tables and make your adjustments.

[Puffer Fish]

You raise an interesting question....

A lot of computers will allow you to change how agressive the profile is...and you can obviously just adjust how much time left on the dive you decide to allow.

Mine, you can adjust a lot of the calculation values, and put extra safety margins in, however, I would doubt they would ever exactly match the same as jumping to the next time group... and doing so means that you would have to remember to put it back..

If you are going to do that, I would suggest just calculating how much less time you want the dive to be and call it at that point...

[Ryanh1801]

Thanks for all the suggestions guys. Guess if I feel like I get really cold on a dive Ill just use my tables and if not just use the computer. Im gonna read through the manual again and see if I can figure out if there are any adjustments to be made.

[CompuDude]

The vast majority of computers have settings for extra conservatism. Add a blip of conservatism if you're worried, else don't worry about it.

It's really only a concern (maybe) if you're riding close to the NDLs anyway.

[in_cavediver]

Stop thinking technically here. Engage your brain! You can and should adjust your profile based on how you feel during each dive and the day in general. If its cold, then don't stay as long. If you uncomfortable, don't stay as long. Just because the computer says you can doesn't mean you have to or that you should!

Computers are like tables, they can only account for time/depth. You have to account for environmental factors yourself. IE, adjust the NDL *you* are willing to stay.