Darwin Awards of Diving

[Mr Carcharodon]

If you are going to get really concerned about a few minutes of deco what do you do when your computer is within it’s NDL but your buddies is not? You do realize this happens all the time when different computers are used. Your less conservative computer did not alter your physiology to make it OK to get out of water sooner. And doing so is not necessarily an inappropriate risk although it could be. The line is fuzzy and broad.

Using probability to predict outcomes may be appropriate for populations but not for a single diver who is diving consistent profiles and conditions. Mr Darwin diver may have been doing a dive that he had done many time before for all we know. That might mean that he had a firm basis to make that dive if not all the dives that lead up to it.

 

[ScubaSteve]

If you are going to get really concerned about a few minutes of deco what do you do when your computer is within it’s NDL but your buddies is not? You do realize this happens all the time when different computers are used. Your less conservative computer did not alter your physiology to make it OK to get out of water sooner. And doing so is not necessarily an inappropriate risk although it could be. The line is fuzzy and broad.

The line is clear for me. Dive the most conservative of computers (in your group or buddy pair) and enjoy being below the surface until the last of the computers clears. I love diving so this really is not an issue. If air becomes an issue......well then we planned poorly and the decision becomes even clearer.

 

[Hoomi]

...what an idiot! ....doesn't he know he can just remove the battery and reinstall it to stop those pesky alarms ? FOOL !

Actually, from what I've heard it depends on the type of memory used in the computer. Older models would lose their memory when the battery was removed, but newer models are using flash memory that isn't erasable by power interruption. One of the things we tried on my Gekko was removing the battery, and the error remained with the same numbers as before. If the memory had cleared, the faulty sensor would have started counting down the depth all over again, rather than continuing the count from where it was before the "hard reset".

One of the things mentioned in the Gekko owners manual is that there is software and a connect cable available only to dive shops, so that they can clear and reset rental models between customers. If clearing was as simple as just removing the battery (which is not difficult on the Gekko), I doubt they'd sell too many cable/software packages.

 

[Guy Alcala]

I like Suuntos; I use an old Suunto Favor that I bought used out of a rental department and have never had any problems other than the #@$%&* touch contacts when the unit is wet and I'm trying to call up the log, but I've learned how to deal with that. I prefer the primay display on Uwatecs a bit more, as my primary interest is depth and dive time: On a Uwatec they're side by side on the top line and about the same size, on the Suuntos depth is on top (or top left), dive time is bottom right, with NDL in between. But it wasn't just the Gekkos that were having problems with the depth sensors; I know the depth sensor on the D3s were failing pretty regularly about the same time. You could search SB back about that time and find plenty of posts.

The problem seems to have been a bad batch of sensors from a supplier; I don't think it's an inherent problem to Suuntos, as I haven't seen or heard a similar volume of complaints recently. But maybe I just haven't been paying attention. If it's out of warranty you're probably SOL in any case.

Guy

Found this thread from earlier this year, although it appears that most or all of the computers involved dated from that bad batch:

http://www.scubaboard.com/forums/co...dent.html?highlight=suunto+gekko+depth+sensor

 

[Lucy's Diver]

It could be done. But I can't picture a scenario where it would be necessary. If I blew an o ring, I would just let my buddy know and surface. Yes, we could both stay down, breath from his tank and replace my o ring....but...I'd still probably just surface.
We'd use up a lot more air (most likely it would blow early in the dive with more pressure in the tank) fixing it under water. If we both ascend on his tank, we could continue the dive after replacing the o ring.

Sorry of this has been covered, didn't read the whole thread.

Here's when you have to do this. You're a tech diver with double 120s full of air, a steel 40 with 36% under your left arm, and a steel 40 with 100% O2 under your right.

You incure your planned deco obligation. You accelerate the deco, as planned, with the EAN and then, and 15 feet, the 02. As soon as you crack the tank with the o2, the reg free flows. Shut down tank, switch to back gas, remove the regs from your deco gas tanks, place the reg from the 36% tank (which worked fine) on the o2 tank and complete deco.

Its bad for the regs (you are getting salt water into places that are supposed to be dry) but it will work. Get the regs serviced prior to the next dive.

 

[Jax]

What happened to the Darwin Awards of Diving? This started out funny?!?!

 

[Bonairetrip]

Using probability to predict outcomes may be appropriate for populations but not for a single diver who is diving consistent profiles and conditions. Mr Darwin diver may have been doing a dive that he had done many time before for all we know. That might mean that he had a firm basis to make that dive if not all the dives that lead up to it.

From a purely academic point of view, I understand your point. Here are the problems:
a) Populations models are the best predictor we have unless everyone wants to push the limits at each depth/time and residual nitrogen level to create their own personal table;
b) Even in that case, in the real world, conditions almost always change. The current is more or less than it was the day before. It is a bit cooler or warmer than it was three or six months ago.
c) Profiles almost always vary, if only by a little bit. Descending a little faster because someone in your group rockets to the bottom. Or you see something cool. Or you have a reverse squeeze and you have to descend and work your way up slower than normal. Or you see something cool at the end of your dive and stay for a minute or two extra. Or your go about five feet deeper than your plan. Or you do tons of swimming. Or you ascend quicker than normal.
d) Your conditions vary dive to dive. Did you party last night? How much sleep? Dehydrated? Getting older? Fighting a cold? Fitness level changed? Are you more stressed than normal (task loading, new gear, viz down, eyc.)

In other words, his profile works for him right up to the point it doesn't.

 

[Bonairetrip]

In the spirt of the thread: The story of Richard Pyle.
Confessions of a mortal diver

 

[Bonairetrip]

If you are going to get really concerned about a few minutes of deco what do you do when your computer is within it’s NDL but your buddies is not? You do realize this happens all the time when different computers are used. Your less conservative computer did not alter your physiology to make it OK to get out of water sooner. And doing so is not necessarily an inappropriate risk although it could be. The line is fuzzy and broad.

I agree that computers are simply running models. We would also agree that the DCS risk of a diver that avoided going into deco status by one second is about the same as a diver who stayed two seconds longer and went into deco status by one second but otherwise had the 100% same profile. I suspect we would also agree that there are undeserved hits that happen to divers and plenty of dives that "should" result in hits that don't. I also agree that two different computers worn side by side on my wrist might yeild different results.

All of that said, the answer to your question is, for me, very simple: both parties make the stops plus the normal three minute safety stop. Of course I dive a conservative computer on purpose (figuring the whole risk/reward/consequences thing). And I also make deep stops even though my computer does not require them when I am doing deep dives. See Deep Decompression Stops

 

[fnfalman]

I have a Darwin Award story to tell. The good thing was that he didn't die, the bad thing was that he did take a DCS hit and ruined the rest of the day for the other divers because we had to pack up & head inland to meet up with a US Coast Guard chopper to take him to the hyperbaric chamber.

We were on a 2-days dive trip on the Peace dive boat, diving the Northern Channel Islands. Beautiful dives on both days, but especially on the second day. On the third dive, this guy stayed down at the bottom too long and ran out of air to do a proper deco stop. Sure as the sun rises in the East, he got bent - difficulty breathing, tingling sensations, etc. The worst part was that he's a rescue diver for his fire department.