Do I really need a computer?

[zeN||]

My Versa Pro Rocks, who'da thunk you could get a computer to mount on your wrist! (Can't seem to find the game section on it yet, you know, 'Pong' or something like it)
I guess you guys who don't use a computer have a depth gauge at least, to determine your rate of descent and deco stop? I know you can rise 'no faster than your bubbles' to time your rate without a 'puter, but that doesn't seem acceptable, seems like a lot of trouble to try to watch your depth gauge and watch at the same time? zeN

 

[Delta_P]

I know you can rise 'no faster than your bubbles' to time your rate without a 'puter, but that doesn't seem acceptable, seems like a lot of trouble to try to watch your depth gauge and watch at the same time?

"No faster than your bubbles" is too fast (at least for the bubbles I've timed).

Count in your head "One One Thousand, Two One Thousand, etc. while checking your depth gauge. 60 fpm ascent rate = 1 second per foot, 30 fpm = 2 seconds per foot. If you want to double check this, note time left bottom and check time every ten feet or at 60 and 30 feet and stop to correct ascent rate if necessary.

After practicing this for a while you can get fairly precise judging your ascent rate with the depth gauge alone, watches and computers become backup and don't need to be monitored continuously during a routine no-deco ascent.

 

[jplacson]

I've always felt that all diving equipment CAN fail during a dive... with or without warning.

I've read about a lot of people whos computers fail during a dive... while I know of some people who have never experienced a computer failure with the computer that they own. Some carry 2 or more... but by some off-chance, all could fail at the same time as well...

as could your reg... and an octo is useless if your 1st stage fails, or it's an OOA or LOA situation.

Just be cautious. If something fails... then ask your DM or buddy to ascend with you. Do a 3-5 min safety stop if you want... or if you're lucky enough to be near a shallow coral reef... just swim around at 15 feet. That way your entire dive is a safety stop... and you get to stay down as long as your air allows

 

[JeffMandell]

Sorry, but I disagree with most of the posts on this topic. If you are a purely recreational diver, staying above about 90 feet, you do not need to use the tables. The computer will do an excellent job calculating the NDC time you have left at any given moment and will time a safety stop for you.

Back some years ago I refused to buy a camera with automatic exposure, believing my use of a hand-held exposure meter and setting the f-stops myself was the only way to be sure. Today, virtually all professional photographers (there are a few exceptions), the guys whose living depends on them getting the exposure right every time, use only automatic and don't give another thought to the computer in the camera that makes the necessary calculation and adjustments. Years before that, my father wouldn't buy a car with an automatic transmission... you get the point.

You do need some sort of back-up to be able to complete a dive if your computer fails while you are at depth. I wear a dive watch that includes depth, time (duh) and an ascent speed warning alarm. This will allow me to ascend safely, including the timing of a 3 minute stop at 15 feet.

Now, what happens to your subsequent dives if you computer fails and you use your dive watch to ascend is a different question. If I'm on a one day dive trip, I might take the chance my day will get shortened, as I don't think the odds are high that the computer will fail. If I'm on a liveaboard for a week, I'll strap on a second computer for every dive; if the main one fails, I can jump right back into the water on the next dive with the spare. But I'm still not using tables.

As for the comment a few posts back,

"Some carry 2 or more (computers)... but by some off-chance, all could fail at the same time as well..."

I'll live with that risk. Probably means there's been a nuclear electromagnetic pulse, in which case the simultaneous failure of all my computers and backups will be the least of my problems.

 

[Uncle Pug]

... need a dive computer.

 

[drbill]

I dove without a computer for my first 38 years. However, my diving was largely single tank and never more than two dives in a day. When I switched to multiple (sometimes 6 or more) dives in a day and several straight days of diving, I felt the need for a good, conservative computer. My diving profiles at home are always multi-level so tables are too cumbersome and inaccurate IMHO.

My advice- depends entirely on the type of diving you do. Square profiles and only 1-2 dives a day and 20-30 dives a year, probably not necessary. Multi-level dives and many dives a day, especially over several days, I'd recommend it.

Dr. Bill

 

[Ari]

It really makes diving easier.

Diving with a depth gage, bottom timer and tables works great. At the same time, due to the fact that most of the dive profiles we do are not totally square, a computer will definitely add some bottom time.

Ari

 

[El Orans]

My computer (Suunto Mosquito) is used primarily as an automated logbook. But then, I usually don't go any deeper than 45 ft.

Since a computer can fail, it is wise to know how to use your divetables anyway.

 

[WVMike]

But, with that said I have one and really like it. I use it more as a bottom timer and still use my log book and tables after every dive.

For me I like the size of the digits on the display. I have not found a watch that is easy to use and has big enough digits.