Am I the only one that dives with 2 computers?

[Superlyte27]

Or get an average depth...

 

[jringold]

I feel like I just threw a turd in a punch bowl with this thread? Maybe I should have asked what is the best certification agency!

Seriously, the technical divers of the group have valid points. I “could” use a table. I learned how during OW training and if I had to, I could come up with a conservative approach for a dive after a failure. But I had the funds and figured why not enjoy as much of my vacation as possible without worrying about failed equipment. If I had more funds, I’d have backup regs, fins, etc. But I could easily borrow/rent most of that if those failed. And I do realize the algorithms are different. But I am extremely conservative anyway and am always at the surface before my computer tells me to take off.

I was mainly just curious if anyone else used backup computers. I am just now getting real dive experience and on a trip recently I took notice of what everyone else on board used.

 

[Zeagle Eagle]

Yeah, I could use a sun gauge to tell the time; but, I prefer my watch. I could use my horse to get to work; but, I prefer my car.

 

[Superlyte27]

And the people contributing are all using a backup computer.... So you have been answered.

But in the absence of a backup computer, you can still dive. Advise staying about from a charter that would impose a 24 hour surface interval after you've handed them 1000's of dollars because they lack the experience to do what we've done for decades.

 

[wetb4igetinthewater]

I dive with a hoseless/AI dive computer on my wrist (Aeris CS 300) and a hose connected Oceanic Pro Plus 2.1. The battery life on the Aeris sucks, and I've had it go out on a dive before. Did I thumb the dive? Of course not. I'm just more meticulous for charging up the batteries before each day of diving.

I always dive with a pony, so I believe in a little redundancy on what I deem important. Others here obviously think differently.

 

[redacted]

Just this weekend was a perfect example of why I dive with two computers. My third drop of the day I accidentally turned Nitrox default 50 to "ON" while changing F02 my primary. I had a new diver on the boat and was more worried about her computer that mine. Damn thing wen't crazy on me at 60 feet on descent. I disregarded my primary and used my backup that was set correctly. Best dive of the day and filled my stringer. If I didn't have a backup I would have to abort the dive.

Backups are always worth it. Also, carry extra batteries for both your computers on the boat.

I have done a similar error, once, using just a single computer. The old Oceanic Data Plus automatically defaults to 50% when diving EAN. Fifth dive of the day, a night dive, and the FO2 was left at 50% and we were diving in the 80 to 90 ft range. Solution, honor the N2 loading limit and manage PPO2 and accumulated O2 manually for that dive and 2 more the next day. It just is not that hard. We did have the advantage of having done those profiles before so we knew I would not have a problem. The next day we stayed a little on the conservative side to avoid a cumulative O2 violation on the computer. These live-a-board dives routinely pushed that rather liberal Oceanic computer into the caution zone for both N2 and O2 loading.

 

[WetLens]

To your original question, yes. And I've done that since the early-90s. My first computer was an Orca Edge. Could not afford two of them, so tables were my backup. In the early 90s, I got quite a deal on Orca Pilots and started diving two of them. Upgrated later to Pilot Eanx and again dove with two. In the early 2000s I got a Wisdom and used one of the Pilot Eanx computers as backup. Recently purchased a Petrel and now using the Wisdom (updated to a Wisdom 3) as backup.

Yes, tables can be a backup, but not worth the effort as far as I am concerned. Limited by square profiles or multi-depth calcs that get complicated. Others may feel emboldened by pulling out their tables, but it is not for me. I still know them inside and out, but not worth going back to that process.

 

[AfterDark]

I have 2 identical computers. I've yet to use both on the same dive. Someday I may get back to NC for a week or weekend, after investing that much money and I want to be able dive even if one computer goes down. For my day to day diving here I normally use one or sometimes none.

 

[Sharky1145]

I always Dive with 2 computers. And when I am going on a boat trip, I take my 2 computers + my Nemo Excel.


Sent from my iPhone usingTapatalk

 

[BRT]

Was 50 min total run time?
Was this dive #1 of the day?
Was this a recreational dive?
What gas were you breathing?

Obviously assuming a 50min bottom time with a square 115ft profile is going to give a major deco obligation. (V-Planner says 48min of deco on 28% for a 50min bottom time at 115ft)

However, with the buddy's computer it would be very easy to run dive #1 through V-Planner as a multi-level dive, set SI time, and then plan and conduct any subsequent dives.

Since we are in the Basic Scuba section lets say 1st dive, Recreational, Air, and computer failure at 50 minutes. If your buddies computer info is good for you why not just continue to dive with it? I don't have V-Planner on the dive boat and don't believe most recreational divers do. But lets say I do have V-Planner on the boat and the second dive is going to be max 60 feet after a 1 hour SI. You certainly are not going to stay with the group! We commonly do dives in Cozumel that would give us that scenario if the computer flaked out at 50 minutes. Tables cannot replace computers until you are into serious tech diving, and even then I don't believe anybody can run multilevel tables to maximize bottom time like a computer can.

For the record I carry 2 identical computers and most people would never notice that I do. And yes, if my dive buddies computer failed I'd hand off my spare to them and we would dive conservatively for the next dive.

---------- Post added September 8th, 2015 at 03:55 PM ----------

I have done a similar error, once, using just a single computer. The old Oceanic Data Plus automatically defaults to 50% when diving EAN. Fifth dive of the day, a night dive, and the FO2 was left at 50% and we were diving in the 80 to 90 ft range. Solution, honor the N2 loading limit and manage PPO2 and accumulated O2 manually for that dive and 2 more the next day. It just is not that hard. We did have the advantage of having done those profiles before so we knew I would not have a problem. The next day we stayed a little on the conservative side to avoid a cumulative O2 violation on the computer. These live-a-board dives routinely pushed that rather liberal Oceanic computer into the caution zone for both N2 and O2 loading.

When the Oceanic defaults to 50% it calculates nitrogen at 21%. In other words if you don't remember to set it, it assumes the worst case of 50% O2 for oxtox and 79% N for DCS. So long as you obey the mod for your tank you can dive it as air and ignore the alarm.