Computer dies, why can’t I continue to dive on tables?

[mike_s]

It can't be too much trouble to take along an extra computer on a live-aboard even if one must borrow...

Which is why we have rentals onboard.

.

Frank,....

from what you see on your boat..... what's the percentage of divers (on recreational trips) of the following that:

1.) bring/dive with a 2nd computer?

2.) rent a second computer if they don't have one?

3.) dive a single computer

4.) dive tables only?


I'm just curious. Just 'numbers/averages' from the top of your head are ok...


Thanks.

 

[Wookie]

Frank,....

from what you see on your boat..... what's the percentage of divers (on recreational trips) of the following that:

1.) bring/dive with a 2nd computer?

2.) rent a second computer if they don't have one?

3.) dive a single computer

4.) dive tables only?


I'm just curious. Just 'numbers/averages' from the top of your head are ok...


Thanks.

1) Very high in the past few years. We are attracting more experienced divers in the Dry Tortugas than we had at the Flower Gardens. Probably 75% or so. The most popular second computer is the wristwatch type, like an Atom. I wear a Stinger every day. It is always set to 21 so it won't reset, and so at least keeps track of my dive in a way I can get the actual data back in the case of a primary computer failure. Primary computer is a Uwatec SmartPro. I use it in Gauge mode for technical diving.

2) Only if they have a low battery and we don't have the correct replacement. This most often happens with VR-3's. We will put a second computer on the diver in this case so if the primary computer fails, at least they have some of their dives recorded, and while their whole trip might not be in the backup, at least they have some exposure tracked.

3) Again, that number has dropped significantly in the past couple of years. Maybe 25%.

4) I haven't seen a diver actually dive tables in about 4 years. Tech divers are an exception. They usually dive tables, although tech computers are becoming more popular.

What you haven't asked about is the Rectal-Cranial inversion factor. Some divers do actually bend their computers. If you really violate deco, our procedure for an omitted stop is to return the diver to the water with a DM, and satisfy the remaining deco obligation, with an additional 10 minutes on deco. This is done on 32% unless the diver has a Deco Procedures card. I keep my O2 stage on the boat at all times for this. If the diver's computer has unlocked, they are free to continue their diving with a stern lecture from me. This has never happened, as no computer has ever unlocked. During my safety briefing, I ask all divers with a Suunto computer to raise their hand. It's amazing the market share that Suunto has. Anyway, I brief them that 1: Suunto computers reset the Oxygen/Nitrogen mix (for nitrox diving) during the Surface Interval, so be sure to check before entering the water, and 2: Suunto computers will give you a 10 foot hold if you violate ascent rates. If you violate this hold, the computer will lock you out for 24 hours. The other information I give them in the briefing is to be sure they hit the start button on Sherwood hockey pucks before getting in.

Now. If a diver gets to 40 feet and finds their computer reset the N2/O2 levels, they may return to the boat and reset the computer. No harm, no foul, get back in and continue the dive. If the diver forgot to turn the computer on and they return to the surface and the computer does come on, no harm, no foul, continue the dive. Many (most) divers choose not to do that. They choose to ignore the blank screen/screaming computer and continue the dive. Those are the folks who don't get much sympathy or help working tables. You've gotta meet this cynical old boat captain somewhere in the middle. If your computer truly failed, due to no fault of your own, you are not likely to miss any dives. If you willfully ignore your dive briefing, and willfully ignore what your computer tells you (remember, I consider the information contained in a computer to be life support information, as critical as a safe and abundant air supply down there), you're probably going to sit out a few dives.

 

[Scott L]

this thread sounds like a good argument against using computers altogether

But, then how would you post?

I just caught that. Post of the week!

 

[LiteHedded]

He means it doesnt matter if you hang a little bit longer just to be sure.

oh I'd agree with that. on repetitive dives I lengthen my shallow stops a tad

 

[Paladin]

All these threads about computer failures continue to reinforce my aversion to dive computers. You guys can do what you want, but I'll just stick to my tables. Using them is second nature to me and they have served me faithfully for 45 years without a single failure.

 

[Token]

Folks - This is one of the most useful [if not THE most useful] discussions I have ever read on any Internet forum. Now I know why I need a backup computer, and why I need to review my dive table understanding before every dive trip. Thank you all.

 

[vladimir]

Anyway, I brief them that 1: Suunto computers reset the Oxygen/Nitrogen mix (for nitrox diving) during the Surface Interval, so be sure to check before entering the water, and 2:

Better yet, tell them to set MIX2 (for those models that have multi-gas capability) to 22% or more, and MIX1 will no longer reset to the default 21%.

 

[jd950]

Since most of the posts in this thread seem to anticipate the diver is on a liveaboard or other dive trip, and such trips typically cost us thousands of dollars per year, not to mention what we all spend on regs, BCs, pony tanks, etc., etc.,.....why not buy a backup computer and put it on your wrist, clip it to your BC or put it in a pocket?

Every other "solution" is either complicated, ineffective or dangerous (or some combination of the three) or requires knowledge beyond what most recreational divers are going to want to acquire and remember.

All are a workaround to problem with a simple and comparatively cheap solution. I just checked and found a basic wrist mount computer of just about any brand/ type of algorithm you could want for under $300.00 each, and most for about $150-$200.

Is it worth $200.00 to not lose 24 hours of diving or try to guesstimate what you can safely do on the next several dives, and/or to risk getting bent or worse, or to have to dive tables for the rest of a dive trip? It is to me, and I take two computers on every dive. An Oceanic GEO is easy to carry. So far it has never happened, but if my main computer craps out, it will make no difference to my dive day.

For those with an aversion to computers, you are not using one anyway, so none of this matters....

 

[diverdoug1]

When on a liveaboard I use 3 computers. 1. a Vipers 2 connected to my high pressure console. 2. a Suunto Stinger. 3. a Gallileo Sol. I also log my dives and carry tables. It is a bit of a hassel adjusting 5 computers every time the pO2 varies in the nitrox bank (my wife makes me adjust hers as well )

 

[TSandM]

A lot of us who have gone to running our wrist adornments in gauge mode have gotten there from bending computers that reset the mix on us. It happened to me in Cozumel -- and I quickly realized what the computer had done, and knew that I was going to ignore what it was telling me. Suuntos really don't like being ignored, so this one decided to sulk and refuse to go diving for at least 24 hours. Exit Suunto.

Today, I allow the VPM software on my X1 to run, because it doesn't hog the display, and because if I don't do what it says (which I sometimes don't, because sometimes I forget to gas switch it at gas switches) it will shrug and deem me an idiot and go diving with me again anyway. Since my deco planning is not done with that software, I don't care.

There are approaches to managing your decompression that don't put you at the mercy of instruments which are designed by people who have liability lawyers breathing down their necks.