Rec Dive Computer for Tech

[DevonDiver]

I'd say spend $50 on vPlanner, another $10 on a wrist slate and use the other $1400 to go diving.

Ditto, it's done me proud for 15 years. I use Multi-Deco now (the latest variant of vPlanner) - it has a good range of algorithm options so I can sync with whatever divers/students bring to the party.

Diving mostly square profile deep wreck dives, there's very little need for $2000+ investment in computers. Appropriate bail-outs and contingencies in my wetnotes means I'm not overly disadvantaged against a computer user.

On the other hand, I put the money to actual diving, not flash kit... logged 29 technical dives in the last month alone, some trimix, some technical wreck, some exploratory, some training.. that's money well spent

With a dive computer, a failure means you no longer know what the pressure is in any of your tanks, or your depth or your time or where your deco stops should be or how long.

There's absolutely no justification for technical diving without some form of critical information redundancy. Computer + bottom timer/tables, used in any order, two tables/timers or two computers is a minimum requirement. Or Ratio Deco...

 

[ianr33]

I'm a big fan of computers for tech diving. Mine sits on my desk next to the printer.

I am also a big fan of computers for technical diving. Mine sits on my left wrist.

If it dies on a dive then plan B is to follow my buddies computer and pad deco a bit. (so shoot me, our profiles will be really similar)

If my computer dies,and I lose my buddy, or his computer dies as well, then plan C is to fish out the wetnotes ,decide which conservative tables to use, and follow my bottom timer.

Opinions vary.

 

[tracydr]

That's nice; I, too, have moved on from the Cobalt (though I'm smart enough to avoid Liquivision like the plague). Did you have a point that actually relates to my post and your earlier comment (regarding whether new divers were steered away from tech computers because it made deco diving "too easy")?

One of your arguments was that tech computers are expensive. Yet, you bring up a recreational computer that is $400 more than my tech computer. That was my point.

 

[fsardone]

Opinions vary.

I subscribe to that.
I use an heinrichs weikamp OSTC 2n as primary (OC/CC capable with 5 'normal' gasses and one additional mix that can be set underwater (in term of oxy/He) and as a backup a Suunto Vyper in gauge mode.
Neither of the two gives me deco. This is done by Vplanner VPM-B alghoritm which gets printed and laminated and attacched to my wrist.
Usually my table is more conservative than my computer (set at Buhlmann with GF with GFlow at 15% and GFhigh at 85%). This is obviously due to the fact that Vplanner uses a square dive but the computer uses actual depth and time.

This gives me a pretty good feeling about I much safety has been padded in my profile and provide a good monitoring for the quality of my plan. Also it is an emergency backup: I could safely surface as early as my computer says it is safe.
I also dive solo sometime and a backup of everything is essential (2 dive computer giving me time and depth plus tables covers that) and having SPG for each tank (I have 2 for my back mounted twins, one for each bottle) covers for failure of transmitters and a single display ....

Bottom line: there is so much to know about tech diving that trying to buy a good tech computer that covers (some/all or a few of) your needs require to build experience and make personal choices that need to be delayed a bit. Buy a cheap one with a gauge mode learn to dive and evolve your equipment with your experience and needs.

Hope it helps

Fabio

 

[ianr33]

Buy a cheap one with a gauge mode learn to dive and evolve your equipment with your experience and needs.

That is always my advice when this question comes up. An inexpensive nitrox computer with gauge mode can obviously be used on recreational dives. For "tech" dives it can be used in gauge mode. If an expensive trimix computer is purchased down the road the cheap computer in gauge mode is still needed as a backup

 

[CBK]

Hey Devon,

Do you use two watches and depth gauges or a gauges (like the uwatec one) and your tables? Or do you use two old recreational computer in gauge mode?

 

[DevonDiver]

Both of the above. I specifically use my old Vyper on gauge mode and an Uwatec bottom-timer.

Many of routine technical dives are training dives (instructor), so I am always on tables (multi-deco/v-planner/gap) for instructional purposes.

To be honest, diving typically square-profile wrecks and following the dive plan explicitly, I don't see much variation between tables and computers anyway. I can match most computer algorithms on my laptop... and there is typically less than a couple of minutes deviance between my written deco schedule and those created by buddies with computers. I do, of course, have 'bail-out' contingencies to permit earlier ascent and longer/deeper, where applicable.

It can be a little more 'prep' work producing written schedules, but I balance that against the benefits of keeping my skills (especially as an instructor) 'fresh and live'... and, of course, the 'small' matter of $2000+ investment on computers. I dive a lot, so kit tends to break/fail within shorter timescales... any big investment in kit has to be balanced against a tangible pay-off in respect to hard capability and attributed to a realistic life-span.

If money were no object, I'd get a couple of Petrels. Money is an issue though... I'm a diving instructor. LOL

 

[ianr33]

If money were no object, I'd get a couple of Petrels.

I don't see a need for 2 computers. Want,yes.Need,no.

So, if your single computer dies on one dive in 100/1000, what's the worst that can happen? Go to bottom timer and worst case tables and do more deco than you really need to do.

 

[100days-a-year]

VPM-A,0 conservatism,2 cheap rec computers in guage mode,add time from 70 on up depending on how square the profile was and exertion level...money saved not having flash gear was spent on gas.Now I mostly get paid to dive and use a 30 yr old computer to do extreme repetitive diving multiday trips in 50-180' with the occasional deep dive done with more modern equipment.

The money spent on training is far more important and should precede any consideration.

The group one plans to dive with should be taken into consideration,not everyone's dive philosophies are similar...particularly among tech anoraks,I mean divers.

 

[DevonDiver]

Go to bottom timer and worst case tables and do more deco than you really need to do.

Which, depending on the dives you undertake, can mean you need to carry a lot more gas than necessary. Considering helium costs, that can be a deceptively expensive 'saving' to make.