What's the best Wrist Mount Dive Computer for both tech and recreatonal diving & why?

[MikeFerrara]

madmole once bubbled...
VR3 tells you ALL stop depths and times while on the dive and total time to surface amongst tons on other stuff

I would like look one over. However in many situations what you would need to know is what your ascent will look like at the time you actually start it (sometime in the future) as aposed to if you started it now now.

Clasic example...
Your on your way out of a cave and have a significant decompression obligation. You notice a team mate is missing. How much time and gas can you use to backtrack to look for him. Does a computer answer that question for you? If so how? How else might you answer the question?

 

[madmole]

Agreed, no computer can do that, but thats what Brains and buddy lines are for

The caves I dive in are so bloody small you couldn't fit 2 divers in anyway, so I'm always solo

 

[Scuba]

MikeFerrara once bubbled...


I would like look one over. However in many situations what you would need to know is what your ascent will look like at the time you actually start it (sometime in the future) as aposed to if you started it now now.

Clasic example...
Your on your way out of a cave and have a significant decompression obligation. You notice a team mate is missing. How much time and gas can you use to backtrack to look for him. Does a computer answer that question for you? If so how? How else might you answer the question?

Good point Mike, while present computers may not provide these types of forward projections, they would be easy to incorporate in the program. I supposed if enough divers asked for this feature some manufacturers would respond to the demand.

What a computer will tell you is where you currently stand based on existing conditions, not forward projections subject to change. Both useful feature in some cases.

While you may correctly project you have X gas and time. Changing conditions, such as stress and its affect on gas consumption, for example, may require on the fly adaptation of existing projections.

Granted I'm not tech, but from all the various points discussed I have to say that for me, the advantages of using a computer for precision and redundancy, outweigh the disadvantages.

But what I don't do is knock those who choose not to use one. Unlike what is common practice in many discussions here by the zeolots on this board against computer use, as though this confirms their point and provides some type of justification. Sorry to keep rehashing this issue, but it gets tiresome.

Edited to clarify a point.

 

[Genesis]

I don't knock people who choose to dive tables.

I do, however, have a problem with the "STROKE!" screams that come from SOME folks who choose to use tables when they see someone appear with a computer, or the "YOU'RE GONNA DIEEEEEEE!" hyena act.

I believe that computer use in diving, like many other decisions, is a choice. One that should be weighed with all the evidence on the table, not simply dismissed because some religious path says that they're evil.

Unfortunately when you dismiss a particular path then you've voided the debate and simply dictated a "correct" way to do things.

Unless you can back that up with some proof, I remain skeptical at best.

 

[Scuba]

I wasn't referring to you Genesis, in fact we couldn't agree more on this issue.

I think you know the ZEOLOTS I'm talking about. I'm just tired of advertising for them.

By the way not all DIR's are zeolots, the majority? At least many of those who post on the internet

 

[Northeastwrecks]

Scuba once bubbled...


Good point Mike, while present computers may not provide these types of forward projections, they would be easy to incorporate in the program. I supposed if enough divers asked for this feature some manufacturers would respond to the demand.

What a computer will tell you is where you currently stand based on existing conditions, not forward projections subject to change. Both useful feature in some cases.

While you may correctly project you have X gas and time. Changing conditions, such as stress and its affect on gas consumption, for example, may require on the fly adaptation of existing projections.

Granted I'm not tech, but from all the various points discussed I have to say that for me, the advantages of using a computer for precision and redundancy, outweigh the disadvantages.

But what I don't do is knock those who choose not to use one. This seems to be a common thread in many discussions here by the zeolots on this board, as though this confirms their point and provides some type of justification. Sorry to keep rehashing this issue, but it gets tiresome.

First off, I'm not actually part of the "computers rot your brain" group. I use a computer (Suunto Mosquito) as a backup bottom timer on my so-called "tech" dives.

The reasons are simple. First, it does function as a timing device and is therefore an adequate backup by DIR standards. Second, it addresses some of the "Oh, sh*t" factor that results when you get into trouble. Specifically, if the dive does straight down the tube, it gives me a comfort level to know that I've got something that will try to get me up alive and unbent.

Its not the use of a computer that strikes me as a problem; rather, its the unquestioning reliance upon a computer during a dive and the substitution of a computer for proper pre-dive planning that are areas of concern. IMHO, it is critical to have the dive profile in place (and commited to memory) before you set foot near the water. You can plan contingencies and have a plan of reaction ready to go. You are not stuck attempting to replan on the fly.

I've have seen divers who are running deco profiles simply jump in, go down and come up when their computer tells them to do so. They don't account for SAC rates and they don't have any backup if their computer fails. That's just plain dangerous.

I've also seen nontechnical divers with air integrated units who rely upon the computer to tell them when to ascend. They paddle around until the thing beeps. I won't even comment.

The other factor to be considered is whether the upside of a computer outweighs the downside. The upside is that the computer will monitor your profile and use its model to plan your deco. The downside is that I want to know my profile before I get to the water. In addition, a computer is more likely to fail than a dive slate (and I carry two copies of my profile in case I lose the slate).

My plans always include 5 minutes over, 10 minutes over, 10 feet deeper and 10 minutes over/10 feet deepter contingencies. I know what will happen at the moment I make my decision to violate plan. As MikeFerrara said, you can't do this with a computer.

It would need to be an extreme event to send me totally outside of my profile contingencies. If such an even occured, it is possible to recalculate your profile based on the original baseline plan. In my case, the amended plan could be compared to the computer; however, it would not be absolutely necessary.

Madmole and I debated this in another thread. His poll shows that most computer divers plan their dive on a desktop to baseline their dive, then use the computer on the dive. I don't see the benefit to using the computer in this case. However, what's important is that the in depth pre-dive planning is still taking place at the appropriate time. I do wonder what would happen if the computer told you something radically different than the dive plan, but that's not at issue in this thread.

Finally, since I've seen two hoseless air integrated Vytec's fail when surrounded by large quantities of metal in a wreck, and because there is absolutely no advantage to this configuration, I stand by my statement that these units are wholly inappropriate for tech diving.

 

[Genesis]

I see the arguments on both sides.

Just like the SPG/Wireless advocates - there's a set of arguments on both sides there too; the analog SPG cannot calculate your PRESENT SAC and tell you that your well-planned dive just went out the window due to excessive gas consumption. They can fail. So can a mechanical pressure gauge - needles can stick, the spool can leak or blow, there is a VERY tiny orifice in the end of the hose that can get plugged with a tiny piece of debris, etc.

All devices have failure modes. If you're going to get in the water in a situation where a direct ascent is not an option, I argue that it behooves you to look at ALL the failure modes that your kit has, figure out which ones will kill you and which will merely inconvenience you, and then make whatever adjustments you believe are necessary.

Ultimately, there is no "correct" choice in most of these matters - there are only risks and benefits, and each diver should be tasked with evaluating them and making their own decision.

My disagreement comes with those who try to play up the risks of one approach, while trying to deny that their pet choice has risks, or claiming that "oh that can't/won't happen".

No matter which side of the argument one may be on.

 

[Scuba]

Notheastwrecks,

As you and others point out a computer is not a failsafe solution to all the problems a diver encounters in planning and executing a dive.

Different people will decide to incorporate them or not based on their personal assessment. What is an issue is when there is an attempt by some to wholey dismiss this very useful tool as though it provided no benefits. This is a disservice to all divers interested in the matter.

Just to reiterate a few points.

Error is possible regardless of method used, computer or brain.

You can not know your dive profile before it happens. You can only plan for one.

When an error occurs you go to your contingency plan.

You have made your decision and I respect it, other have decided differently, as I have, for what are also legitimate reasons, and I respect them as well.

 

[Northeastwrecks]

Scuba once bubbled...
Notheastwrecks,

Error is possible regardless of method used, computer or brain.

You can not know your dive profile before it happens. You can only plan for one.

When an error occurs you go to your contingency plan.

I don't disagree as far as those statements go. However,

1. I accept that failure is always possible. My goal is to minimize the chance of failure by selecting equipment that has the least chance of failure and maintaining situational awareness.

One of my goals when diving is to estimate my remaining gas to within 100 psi without looking at the SPG. I'm getting pretty good at it. So even if the SPG (or computer) failed, I still have a pretty good idea of my situation.

2. That's true, which is why I include contingencies (I forgot to mention that I also include a bail out profile for half the planned time). My concern is that a computer won't let you see the effect of a plan change until after you've done it. In other words, a preplanned profile will tell you what will happen if you overstay your welcome by 5 minutes. You can evaluate the choice in advance. As far as I know, a dive computer won't give you the bad news until after its too late.

3. Yup. I'm curious, however, whether a computer can provide your contingencies before you get in the water. For example, is there a dive computer with a plan mode that will allow you to predict the effect of a 5 minute increase in bottom time on remaining gas and deco? That would be something I'd be interested in seeing.

Essentially, it comes down to this. Its not the mere use of a computer that is problematic. Its the lack of situational awareness that can develop as a result. I don't really have a problem until that situation arises, unless the computer in question is a hoseless air integrated model or something else that is completely inappropriate for technical use. I'd abort any dive near a metal wreck or any technical dive if my buddy was using a hoseless computer.

 

[Uncle Pug]

What's the best Wrist Mount Dive Computer for both tech and recreatonal diving?

The best wrist mount for both tech and rec would not be a computer per se but a bottom timer/depth gauge that also included a count up timer such as the Suunto Stinger or D3.

Why?

1. Using the same gear in the same manner for both rec and tech makes sense to me... when things go sideways in a tech dive you don't need the added distraction of remembering what you are using and how you are using it.

2. The discipline needed for tech diving can be practiced on rec dives. Keeping track of ones profile during the dive rather than letting a computer do this for you is very important... and the skills learned and honed on rec dives will serve you well on tec dives.

3. Learning to time stops using a count up timer while rec diving is a valuable skill that will pay dividends on tech dives where keeping track of time spent at stops and judging intuitively the time it takes to get from stop to stop is very important. The count up timer on the Suuntos is very good for this.