Am I the only one that dives with 2 computers?

[Dhboner]

It's a question about a problem that doesn't exist. If you have computer than can be run in gauge mode, you do so because for whatever reason, training, skill review etc. you want to dive using either ratio deco or tables you cut but regardless you want to dive in "manual transmission" mode. If tracking tissue loading is an issue then don't put the computer into gauge mode...simple enough. It's one of those questions that seems more than just a little bit silly.

 

[tbone1004]

ok, pardon me for skimming through the last few pages.

Gauge mode with tissue tracking is pointless. The algorithm determines two things as a function of PN2/PHe and time.
1. Tissue loading in x-number of compartments, both ongassing and offgassing rates for these compartments
2. The maximum saturation percentage allowed to surface that is determined by part 1.

If you are running computers with identical algorithms, there is no point in having one of them in gauge mode. If you are diving computers that don't care if you bend them, i.e. Petrel, then there is no point in running in gauge mode. Even if you're running tables or ratio deco, you can just leave it in computer mode and set it to a GF that is less conservative than you are diving. I.e. for ratio deco set it at 45/95, and you'll always clear the computer first and you can just use it as a sanity check to make sure you did the math right.

 

[Michael Guerrero]

It's more common with technical divers. For recreational divers, if your computer goes out you're "supposed" to surface safely. Technical dives may not allow for that.

I wear two computers every dive, so you and me both I guess.

 

[scubasteeeve]

However, unless others had their backup hidden in an orifice somewhere on their body, I was the only one diving with two computers. Just wondering if anyone else dives with two computers or am I being overly paranoid about a computer failure (and screwed up 24 subsequent hours of diving…)

I wear a computer but also wear a watch and do manual tables/notes on my slate pre and post dives as well. My zoop and sei tables are pretty much identical in the p0 setting.



Sent from my iPhone using Tapatalk

 

[Lorenzoid]

If you have any intention of using gas loading info from a computer during a current or subsequent dive, why would you want to set it to gauge mode rather than dive mode?

I think the premise that started this side discussion is that the diver is concerned the "backup" rec computer might at the very least issue annoying NDL violation warnings, and at worst lock the user out (as some rec computers do). As I've said, I don' understand why this mode would be needed, either.

Fot the whack are you guys talking about? Off the top of my head, Aeris A300, Manta, Hollis DG03, and Oceanic Geo 2 all have "free" mode that tracks N2 loading based on air and carries it over to dive mode if you switch mid-trip. At least that's what their manuals claim -- I don't personally own any of them.

I wasn't aware that any computer allowed that. I figured computer manufacturers didn't want divers using Gauge Mode (or "Free" mode or whatever one wants to call it) as a way to circumvent the computer's NDLs on repetitive dives. What do you mean by "mid-trip"? Would it allow you to do the first dive of the day in Gauge (or "Free") mode and then during the surface interval switch it to Dive Mode?

 

[islanddream]

I'm really glad I wear two computers. Case in point....went on a Goliath Grouper dive on Wednesday and my oldest computer decided to not work properly after being in the water about 10 minutes. My newer computer worked just fine and I was able to complete the dive. Too bad the weather sucked and we didn't get to do a second dive!!!

 

[dmaziuk]

I wasn't aware that any computer allowed that. I figured computer manufacturers didn't want divers using Gauge Mode (or "Free" mode or whatever one wants to call it) as a way to circumvent the computer's NDLs on repetitive dives. What do you mean by "mid-trip"? Would it allow you to do the first dive of the day in Gauge (or "Free") mode and then during the surface interval switch it to Dive Mode?

Like I said, this is what the manual says: in "free" mode it'll track your N2 loading and it will be carried over to "dive" mode if you switch to that.

I agree that it seems pointless in a "lite tek" or better DC. My "strictly rec" Cressi Leonardo's programming is limited to 40m, but the gauge is rated to 80 or more, I don't recall exactly. I also forget if it locks you out for NDL violation or not, let's say it does. So I can see why, as a backup on a dive below 40m and/or beyond the NDL, it'd have to be in gauge mode. As a backup on a strictly rec dive -- just leave it in dive mode, what's the problem.

And besides once you give them the "free" mode they'll start whining "it's too conservative: I was diving EAN32 but it calculates N2 loading for NEA21, it can't read my mind, it's total garbage".

 

[JS1scuba]

Unless doing pool training with OW students I always dive with 2 computers that are matched in brand or algorithm.

My go-to everyday units are (2) Cochran EMC-20H My next set are Scuba Pro Galileo Sol and ScubaPro Aladin2 (aladin in pocket) and the third set are 2 Liquivision XEO. Granted i do this for a living and have a lot of gear, but two is what is needed.

Remember 1 is none, two is 1.

Cheers

 

[Erik N]

I always dive 2
single tank req dives: petrel (rec mode) and Lynx (air integrated)
sidemount rec: petrel (rec mode) and Lynx (rec mode with ai off)
tec: petrel primary and Lynx on gauge with cut tables and no ai.

i keep a "brass and glass" spg in my rec regulator bag in case my Lynx craps out so worst case scenario, I only have to thumb that dive. If my petrel goes out on a rec dive, I will just keep going following my Lynx.

if you have 2 computer, you should be carrying them on the dive or you will be reduced to diving tables anyway if you have to switch to a fresh computer which kinda defeats the point of owning 2 when you could save money and use depth+timer.

neither of my computers will lock me out, or prevent me from switch from gauge to dive modes, so if I had a tec dive in the morning, I could switch my Lynx back from gauge and dive rec the afternoon, but if my petrel fails, the dive is getting thumbed (only in this scenario), so it's not really an effective backup in that scenario as it wouldn't know my accurate ndl and I'd rather surface to cut new tables then try to fly a computer that was on gauge for a deco dive.

for purely rec diving, if you lose your computer without any means of backup, you should be thumbing the dive and switching to tables, not a fresh computer as I believe someone said. If you are diving a deep rec dive and slowly ascending the whole dive, you are going to be well outside table values, so be prepared to be pressure group "z" and heavily pad you surface intervals and pad your safety stop. If you know you will be diving in those scenarios, you should invest in a cheap backup.

i know I've been on a deco dive with 50 and O2 and here my old dg03 reverted from gauge to dive before I descended and I intentionally locked it out on ascent (no thanks on an extra 50 minute deco) as I was following tables, but that was my last dive on it before buying the Lynx for gauge/backup instead. And the fact I hated the screen not being illuminated and wanted ai for rec single tank (sidemount spg placement is already right in my face).

i don't think it's necessary to algorithm match as you should be obeying your more conservative computer and as a rec diver, should never be in a scenario where it is necessary to blow off a deco stop (or even enter deco) so a lockout shouldn't be an issue.

 

[Lorenzoid]

Like I said, this is what the manual says: in "free" mode it'll track your N2 loading and it will be carried over to "dive" mode if you switch to that. . . .

Interesting to know. Thanks. My Suuntos do not let the user switch modes at will. The manual says: "If you dive with the GAUGE mode, it is not possible to change between the modes before the no fly time has counted down."

It seems Suunto really does treat the diver like a child. I have been carrying a Suunto on dives--in Dive Mode--as a backup to my Petrel, but I can see how its conservativeness might annoy the diver who prefers to dive aggressive profiles.