Depth Gauge or Not

[Steve_C]

and two computers, backup one set to gauge mode

Why. if primary fails then you are done diving for the day while if both are computers then you just finish the dives on the backup computer. Unless you are doing only square profiles.

 

[Steve_C]

You guys with 2 computers.... if you're diving nitrox, do you really remember to set BOTH FO2s each dive... especially if you use different %'s on a single boat trip?

I essentially always dive 32%. get fills ahead of time and do not know depth of next dive. Just that it will be above 111 ft. One computer remembers the mix. Other I have to set. I mostly dive from boats. I have never used two different mixes on the same trip. Note that I don't dive deeper than 105. I like simplicity and using the same mix is simplicity and the few extra dollars on shallow dives does not matter to me..

 

[tbone1004]

I don't know what other Nitrox divers do, but I have no problem remembering to set both of my dive computer to the right % O2. For Nitrox divers, it is a predive routine anyway that you analyze the % O2 in the tank, then adjust the % O2 on the dive computers before plunging into the water. In fact, I always set my dive computers to Nitrox & just simply dial down to 21% O2 if I would dive with air on the next dive.

I've definitely forgot to set my Petrel back to "not-O2" before a dive.... Hasn't happened in a while, but definitely happened probably 3-4 times after I first got it because it doesn't reset back to your default gas which is what I was used to with my old computer. I know several divers that have realized they forgot to take it off of O2 once it started flashing red when they went deeper than 20ft on descent

@Pkishino I am with @Steve_C on this one, the backup computer is set to computer mode if it is running the same/similar algorithm or a less conservative one. My Nitek Q is backup and I usually leave that on GF 70/85 for a get me the hell out of the water decompression profile if I have to, but it never goes into gauge mode

 

[doctock993]

My experience is ONLY with recreational diving in "tropical" waters and travel is always required for me to get to any dive sites - these days most diving is on the opposite hemisphere - so weight/ bulk is an issue.

Was originally taught to dive on dive tables with the use of an SPG and depth gauge.
I equipped my rig with a combo-unit of "micro" brass&glass SPG/ depth/ compass.
I wear a pseudo-mechanical Citizen dive watch with time and back up mechanical depth gauge.

My dive computers have "failed" in one way or another on more trips than I care to count, & my basic backup rig is, in my opinion, invaluable.
Nothing like redundancy, no matter how basic...

 

[boulderjohn]

My dive computers have "failed" in one way or another on more trips than I care to count, & my basic backup rig is, in my opinion, invaluable.
Nothing like redundancy, no matter how basic...

Wow! You have certainly had a run of bad luck! I have never had a dive computer fail, and I have never been on a dive with anyone else's diver computer failed.

As I said earlier, I am not sure what backup tables would do for me in case of computer failure, since a multilevel first dive would take me off of the tables.

 

[Dan]

Wow! You have certainly had a run of bad luck! I have never had a dive computer fail, and I have never been on a dive with anyone else's diver computer failed.

As I said earlier, I am not sure what backup tables would do for me in case of computer failure, since a multilevel first dive would take me off of the tables.

I have same problem. That's why I posted this thread a few months ago: NOAA Nitrox 32 No-Decompression Table Questions

 

[Steve_C]

So a question. Say I am diving only one computer (I don't) and I look at it and see that I have 20 minutes of NDL left and am at 70 ft on 32%, I immediately begin a safe ascent and do a 3 min safety stop by counting the seconds. Can I back engineer my pressure group and try to use tables knowing how much NDL I had befoe left at 70. I do have a depth resistant watch I could take on dive 2. Of course if the next dive is to 20 ft it does not matter since NDL will be bigger than air. But for say a dive to 70 again and assuming a square profile?

 

[Satrekker]

I dive 2 computers and have no problems remembering to set the appropriate gas on each for each dive. My main dc is a Perdix AI on my right wrist, and my backup is a Scubapro Mantis M1 watch style on my left wrist. I also have a brass and glass spg on left hip d-ring. If I have issues with my main or the transmitter, then I have complete redundancy and it's very little additional equipment imo for the security.

 

[Jason]

I love my setup. Simple brass and glass SPG on a short hose clipped to my left hip (no depth gauge). Perdix AI on right wrist. Geo 2.0 on left wrist.

 

[oldschoolto]

You guys understand that we are talking about a gauge that is maybe 10oz.. A pound if you get the biggest one you can find... It's adding maybe 3" to the length of the SPG... This sounds like talking about getting a hose that's 1" shorter so you're more streamline and you'll have a great SAC rate...

And the diver has a camera that is 15lbs and 6 lights sticking out...

Jim..