Why should I get a computer?

[markfm]

Hmmm, I'm feeling a bit off, want more margin, think I'll only dive to four bars nitrogen loading displayed rather than 5. Real rocket science

(I'm a techie, but life's too short -- I don't bother reprogramming them.)

 

[Scubakevdm]

Hmmm, I'm feeling a bit off, want more margin, think I'll only dive to four bars nitrogen loading displayed rather than 5. Real rocket science

(I'm a techie, but life's too short -- I don't bother reprogramming them.)

Or perhaps within 20 minutes of the NDL, or 25 or insert value here.

 

[AbyssalPlains]

but I'm not sure how much more time one would get and whether it's worth it.

I sometimes compare my computer to the tables when diving, just for the heck of it. The result is always the same: The tables either tell me that A) I shouldn't have done the profile I just dove (which is a perfectly safe profile just like everybody else on the boat) or B) that my surface interval for a second dive is something like, as in the last case, 8 hours (as opposed to the hour and a half that my computer told me). The bottom line: If you are OK with going on (and paying for) a two-tank boat trip but doing only one dive or going on a liveaboard trip where you do one dive a day while everybody else gets four or five dives in, stick with the tables. If you'd rather actually dive, get a computer.

 

[Doctor.Lizardo]

Just wanted to say thanks to y'all for the replies. It was particularly interesting to see some of the details as to just how much extra bottom time a computer can buy you and for that reason I think I'll start looking into getting one. Thanks again.

 

[diverdowndh]

I did my first 100 or so dives without one, never had a problem. A couple of years ago I rented a couple different types and then purchased a Suunto Vyper. I absolutely love diving with a computer, just because it is watching me all the time. Because I dove so much using just tables for my logs, I understand most everything being displayed. Yes, it is very much a convenience thing but between the computer b/t my ears and my Vyper (and tables to double check with) I'm pretty confident that I'll be safe.
One downside is that it keeps track of many dives - if you're not really consistent you end up not filling out your log until later. When you do that you have trouble documenting the high points of each dive in the log, so you remember things you saw, things you did, etc. when you look at it later. You only end up with the statistics of the dive and I love to peruse thru my logs and relive all the cool things I've experienced on my dives.

I also dive nitrox, many times just on my second dive, and it makes all the xfer b/t gasses easy. My fiance' and I usually check the logs to the tables on the flights home to double check and just to keep sharp on the tables.

 

[halocline]

PSS. I chose a very very conservative computer (RGBM) cause I like playing it safe when it comes to diving.

PSSS. Flame away!!!!!:no :no

No flames here, but maybe a little hot air. I'm glad you think you're playing it safe by choosing a conservative computer, but statistically you're not; in fact there is no data, none, that demonstrates users of more conservative computers are less likely to get DCS than the liberal freaks. (of which I'm one!)

So far, only one person has listed what I think is the most important safety feature of dive computers, the ascent rate indicator and alarm. Next on the list is the N2 loading bar, which gives you a theoretical but easily interpreted indication of how much N2 you have at the end of a dive when you're about to surface. Want to play it safe? Hang out at your safety stop until the N2 bar retreats well into the "green" area.

Computers use different algorithims to come up with vastly different NDL values in a variety of situations. Therefore, it's important to consider NDL with a grain of salt; more of a gradient than a specific number. Surprisingly, the N2 loading bar on my friend's suunto and my aeris agree almost all the time, while our NDL numbers can be almost an hour in disagreement.

Computers are a convenience and I believe a safety device WHEN USED INTELLIGENTLY by recreational divers. I do have a suspicion that the ubiquitous nature of dive computers at places like Cozumel and Roatan (all multi level profiles) and on liveaboards (lots of repetitve diving) has resulted in lower numbers of DCS cases. I would advise any recreational diver to use one.

 

[quietstorm]

So far, only one person has listed what I think is the most important safety feature of dive computers, the ascent rate indicator and alarm. Next on the list is the N2 loading bar, which gives you a theoretical but easily interpreted indication of how much N2 you have at the end of a dive when you're about to surface.
__________________________________________________
Why thank you kindly, for I think that it was I who was that one person . I am glad to know my two cents worth actually has merit in someone else's eyes.

The positive feedback also is nice since it reinforces what I believe to be safe diving practices and lets me know that, even as an occasional intermediate diver, I am on the right track.

All the little bits of information contained in these SB threads is helpful to me.

 

[CODMAN]

Well don't conservative computers give you lower NDL times? Which if respected, will give you less Nitrogen uptake than if following the NDL of a more liberal computer? I kinda call that playing it safe. But obviously, that's not all you need to be safe and I take many other precautions. I wasn't trying to state that a RGBM computer was the unique element in safe diving...

I also agree 100% with you Matboy, the ascent rate indicator if a great feature!

Cheers!

No flames here, but maybe a little hot air. I'm glad you think you're playing it safe by choosing a conservative computer, but statistically you're not; in fact there is no data, none, that demonstrates users of more conservative computers are less likely to get DCS than the liberal freaks. (of which I'm one!)

So far, only one person has listed what I think is the most important safety feature of dive computers, the ascent rate indicator and alarm. Next on the list is the N2 loading bar, which gives you a theoretical but easily interpreted indication of how much N2 you have at the end of a dive when you're about to surface. Want to play it safe? Hang out at your safety stop until the N2 bar retreats well into the "green" area.

Computers use different algorithims to come up with vastly different NDL values in a variety of situations. Therefore, it's important to consider NDL with a grain of salt; more of a gradient than a specific number. Surprisingly, the N2 loading bar on my friend's suunto and my aeris agree almost all the time, while our NDL numbers can be almost an hour in disagreement.

Computers are a convenience and I believe a safety device WHEN USED INTELLIGENTLY by recreational divers. I do have a suspicion that the ubiquitous nature of dive computers at places like Cozumel and Roatan (all multi level profiles) and on liveaboards (lots of repetitve diving) has resulted in lower numbers of DCS cases. I would advise any recreational diver to use one.

 

[Jupiter31]

Its a fair question and depends on the diving you do - if your dives tend to be shallow - 40/50 feet and below, it does not really matter, especially if you are not doing repetitive diving.

I go back to the "original" dive computer - the Edge - and got one in the late 80's and have been a proponent ever since (maybe because I never could figure those dive tables - what the heck was an "H" or a "J" diver....... I don't miss those days at all, but thats me)- just gives you a margin of safety plus greater bottom time (in most instances). To me, if you are going to dive with any frequency, nitrox certification and a computer are a must. Just my opinion.

I dove Jupiter last weekend and rules were 25 min's of bottomtime on air w/out a computer - w/ nitrox and a computer 45 min's.

You could use an old horsecollar bc - remember those? - and it would provide a measure of safety and boyancy control - but nowhere close to the comfort and functionalty of today's bcd's - probably a bad example but I want everything going for me I can so just like I'd not use a horsecollar I will always use a computer. If you buy an "air only" (not reccomended) they are about $150, probably less on sale - I bought my backup - nitrox ready - for $199.

I'm not a tech oriented guy but I would not dive without one.

They don't replace training, experience, and comon sense.

 

[halocline]

Well don't conservative computers give you lower NDL times? Which if respected, will give you less Nitrogen uptake than if following the NDL of a more liberal computer? I kinda call that playing it safe. But obviously, that's not all you need to be safe and I take many other precautions. I wasn't trying to state that a RGBM computer was the unique element in safe diving...

I also agree 100% with you Matboy, the ascent rate indicator if a great feature!

Cheers!

I understand your point; it's intuitive to think that a more conservative computer which limits your bottom time would be more preventative for DCS than a liberal one, but there is no data to support that assumption. I think this is mostly because: 1) recreational single tank diving has a very low incidence of DCS, making corrolations with any specific factor difficult, and 2) there are MANY suspected factors, some well known, some not so well known, in cases of DCS.

I have a theory that the use of the AL80 for rec diving, especially in rental tanks to occasional divers, is a factor in the low incidence of DCS. For example, in Cozumel, there is a trend among some dive ops to offer much larger tanks so that vacation divers can stay down longer. I would venture a prediction that as the use of these tanks increases, so will DCS cases in Cozumel. The fact that most divers will exhaust an AL80 before incuring deco penalties at typical recreational depths is a big safety feature IMO. I would be happy to be wrong about this; time will tell.