Decompression Stop Guidelines - What we have to do if got deco alert?

[Belzelbub]

A 48 hour lockout demonstrates a fundamental lack of understanding of the nature of that line and that region, that being that it is a continuum of varying risk and the line is not drawn at a peak or a valley.

No argument there. I'm not a fan of lockouts in general, and a 48 hour lockout is extremely conservative, and most likely more based in financial considerations than decompression science. Even then, I'm not sure how much liability we are really talking about. There is at least 1 big corporation that is OK with being able to disable the lockout.

 

[dmaziuk]

You are ass-u-ming that the device's firmware is able to function properly from the starting point of "bent into one hundred nazi crosses" -- as the case would be when the diver omits mandatory deco: as far the computer is concerned, the user is bent.

Schreiner's equation doesn't care if your tissues are over their respective M-values, simplified "folded" RGBM may be a whole 'nother question.

48 hours may be "conservative" but Weinke believed "repetitive diving" window should be longer than 24 hours, ISTR 36 mentioned in one of his papers, so for an RGBM computer it's not necessarily unreasonable to need > 36 hours to reset to "clean slate".

 

[Gareth J]

No argument there. I'm not a fan of lockouts in general, and a 48 hour lockout is extremely conservative, and most likely more based in financial considerations than decompression science. Even then, I'm not sure how much liability we are really talking about. There is at least 1 big corporation that is OK with being able to disable the lockout.

It is only relitively recently that dive dive computers don't lock you out. It was only with the advent of the VR3 that a computer wouldn't lock you out if you violated the decompression profile.

The VR3 used to display "REVERT TO TABLE", and give you a best fix (with potential risk of a bend).

The computers that don't lock you out are those designed for the technical dive market. On the basis that the users are better trained and qualified, and have an awareness of decompression theory. They don't lock you out because there is an assumption that a best fix with a bend is better than drowning. Those doing technical diving are generally trained and equipped to provide on site first aid for DCI prior to medivacing a casualty.

If you look at all the original dive computers, they all stated they where not designed or to be used for dives requiring decompression stops. Despite the fact that they all provided decompression information, and in the later days, allowed gas switching to accelerate the decompression. This was down to one single market, the USA, where law suites are grown around like candy. Stating the computer was not to be used for decompression stop dives removed (in some part) some of the liability. Similarly, to limit issues of liability, they would all lock you out if you violated the decompression profile. The rest of the world just got on with using them to there full potential.

 

[L13]

So, the first 16 pages of this thread are from more than 5 years ago. It was briefly resurrected a year ago.

It was re-resurrected yesterday with a simple question about ...

I have a bad habit of over-reacting to threads like this. I get pedantic, accuse others of being pedantic, etc.

I'll try and do better.

 

[scubadada]

Regarding lockouts.

I dive quite a bit in SE Florida off a number of charter boats. The divers have diverse backgrounds. Several times a year someone asks me why their computer does not seem to be working normally. The usual cause is that they are locked out from missing an obligatory deco stop. They often look at me like I am an alien, no hint of understanding on their face. If only they knew how their computers worked. This happens nearly always with RGBM computers, Cressi, Mares, Suunto, but not exclusively.

I put a backup Oceanic Geo 2 computer into violation gauge mode when I forgot to set it from air to 36% nitrox. Once I was underwater and recognized my error, it was too late to change. That computer was locked out for 24 hours.

 

[BlueTrin]

The no fly time is not related to diving again directly.

I think he was doing this because some suunto will display a 48h lock if you have skipped a stop, he maybe got confused with no fly time and was looking for random stuff to ‘win’ the argument and bench her?

Here is suunto eon page for no fly times

Suunto EON Core - Features - Surface and no-fly time

www.suunto.com

 

[Blackcrusader]

I would avoid that by saying "I did not exceed my NDL."

On one of my recent dives another diver told the owner who was also diving in another group that according to them I must have exceeded NDL as his computer would have been in deco. The owner simply explained I used a Perdix with settings that do not equate to their own DC and explained that my DC often shows a much longer time to NDL than other computers. In fact two of my dive buddies used GF70 whereas I use GF95 so they would start ascending before me to avoid exceeding NDL on their Teric's.

The only requirement is that we do not exceed NDL on the dives. Dive to your own DC settings

 

[Blackcrusader]

The no fly time is not related to diving again directly.

I think he was doing this because some suunto will display a 48h lock if you have skipped a stop, he maybe got confused with no fly time and was looking for random stuff to ‘win’ the argument and bench her?

Here is suunto eon page for no fly times

Suunto EON Core - Features - Surface and no-fly time

www.suunto.com

Except the divers DC was not locked out for missing a stop. Dive center error.

 

[Blackcrusader]

If you don't like 48h lockouts then throw your Suunto away.

My Suunto did me a favour and the pressure sensor failed forcing me to look for a new computer.

Never been happier than to get a "proper" dive computer that uses the Bulmann ZHL 16c

Perdix it was for me as easy to learn how to use, can replace battery, and is easy to read any any conditions.

 

[Centrals]

How difficult it is to follow the instruction given by your own computer? If you don't, replace it with something you believe!
There are all kind of algorithms nowadays but none of them can promise 100% safety.
23 pages on such a easy question? Incredible.