Suggestions for getting my first dive computer

[scubadada]

...Not only is the algorithm the least important part of a dive computer, it is the one user's are least well qualified to judge...

Some of us believe quite differently. During OW, agencies could easily teach the rudiments of decompression algorithms in much less time than it takes to teach tables. Divers would then have a basic background before considering the purchase of their first dive computer. Knowledge, rather than ignorance, is in the best interest of the consumer.

 

[Chavodel8en]

Algorithm is such a daunting word. I dont understand the algorithms, bubble theory, etc. Thats for you all scuba nerds (and I say this with the utmost respect).

But I understand very simply that a conservative computer = less deep time/less risk v. a liberal computer = more deep time/more risk. This is not a difficult concept, its actually pretty intuitive. In fact, I believe the above sentence lays out its essence (and these rudiments were covered in my OW, if I remember correctly)

May as well let a new OW diver know this information and they can do with it what they will. If they care, they should investigate it and choose the appropriate computer. If they dont care, they can ignore it,

To the OP, I advise you to look at the pinned post in Computers & Gauges forum. Lots of good information. And if you care about liberal v conservative computer, that post has a handy chart.

 

[scubadada]

All commercially available dive computers and the decompression algorithms they run, are safe. They have been used successfully by many, many divers, over an extended period of time. For example, DSAT and the very closely related PADI RDP, have been available since 1987. There is no information that any of these decompression algorithms are safer or riskier than others. All have 1st dive NDLs that are significantly shorter than USN tables. Unfortunately, there is little available information on repetitive dives
http://ads.bonniercorp.com/scuba/PDF/ScubaLab-Computer-Test-September-2014-data.pdf There are unexplained episodes of DCS associated with the use of all dive computers and tables, perhaps reflecting the importance of individual and environmental variables

 

[KenGordon]

Some of us believe quite differently. During OW, agencies could easily teach the rudiments of decompression algorithms in much less time than it takes to teach tables. Divers would then have a basic background before considering the purchase of their first dive computer. Knowledge, rather than ignorance, is in the best interest of the consumer.

But they do not teach deco theory to a degree that allows a new diver to judge. Why not? Because it is not required to be able to go diving after the minimum length course that only covers the essentials which is what people buy.

Given it is not taught how are new divers to judge?

 

[KenGordon]

All commercially available dive computers and the decompression algorithms they run, are safe. They have been used successfully by many, many divers, over an extended period of time. For example, DSAT and the very closely related PADI RDP, have been available since 1987. There is no information that any of these decompression algorithms are safer or riskier than others. All have 1st dive NDLs that are significantly shorter than USN tables. Unfortunately, there is little available information on repetitive dives
http://ads.bonniercorp.com/scuba/PDF/ScubaLab-Computer-Test-September-2014-data.pdf There are unexplained episodes of DCS associated with the use of all dive computers and tables, perhaps reflecting the importance of individual and environmental variables

What does 'safe' mean? Zero accidents? Clearly they are not safe by that measure. How safe is safe enough is a judgement call. That requires and ability to make the judgement, that requires being informed. New divers are not informed.

 

[KenGordon]

I find it interesting that some of the people telling the OP what the diving will be like seem to have limited experience, despite their number of dives. My experiences diving around the world differ from what some people seem to think is done in all places. Here are just a few examples:

• In Cozumel, some of the operators, notably Aldora, offer HP 120 foot tanks in order to extend dive times. First dives are usually in the 80-100 foot range, and NDL is very much a concern.
• In South Florida, most of the operators I have used do not put DMs in the water leading dives. Many of the operators offer a wide variety of tank sizes. Depths of first dives can go all the way to recreational limits--130 feet.
• I have dived with a number of operations in the Hawai'ian Islands that had us diving to the limits of both our gas and our computers.
• I just got back from diving in Bali a couple of months ago. Yes, we did mostly group guided dives, but we also did unguided shore dives where depths and times were up to us.

Does your computer make a difference on dives like that? Last year while diving in South Florida for a week with two friends, we used three different computers, and we were limited by the most conservative. As soon as that week was over and the other two went back home, the one with the most conservative computer, who had been totally frustrated during that week, sold his computer and got a different one.

Why not just do the stops? If you are not limited by gas or a nanny then do the stops and get out with less nitrogen.

 

[scubadada]

But they do not teach deco theory to a degree that allows a new diver to judge. Why not? Because it is not required to be able to go diving after the minimum length course that only covers the essentials which is what people buy.

Given it is not taught how are new divers to judge?

What does 'safe' mean? Zero accidents? Clearly they are not safe by that measure. How safe is safe enough is a judgement call. That requires and ability to make the judgement, that requires being informed. New divers are not informed.

What exactly are you arguing? Newer divers are going to follow a table or a computer to guide their diving, regardless if they understand anything about decompression or decompression algorithms. I clearly stated that there are unexplained episodes of DCS associated with the use of all tables and decompression algorithms, you know that. I believe it is in a diver's best interest to have some understanding of the variety of decompression algorithms available before they make the major purchase of a dive computer.

 

[boulderjohn]

Why not just do the stops? If you are not limited by gas or a nanny then do the stops and get out with less nitrogen.

I have no idea what this means.

 

[KenGordon]

I have no idea what this means.

It means, rather than deciding that a computer is cutting a dive short and buying a different computer, why not do the dive you would have done if not so limited and then do the stops the original computer gives you? Say you have 120cuft cylinders and do a 25 minute 30m dive. Rather than get out directly like a 'good' computer might let you, do the 10 minutes of stops a 'bad' computer will give you.

You know, do the actual dive you want to do, then the stops required? Is that so hard?

 

[drrich2]

But would you recommend unplanned deco. single tank diving to non-tech. recreational divers?

How many rec. divers are familiar with how their computer handles going into deco.?

I get that some advanced divers wouldn't consider it a big deal, but a lot of people probably would.

Richard.