Should RBs turn on automatically if you enter water with electonics off?

UKSteve

Gareth, Richard and Phi

I really appreciate all of your contributions and also respect your opinions..and Phi ...hey ...that was a gentle tug on your leg... I was a Company Man offshore....what did you expect

I also agree that we should never find ourselves in that position ...but the simple fact is a number of people have .. and have died.... and it makes me sleepless to think that they might have survived if their units had woken up and said "HEY!!!!!!! What the F$%K are you doing??"

It should not let you continue your dive... but if the warning functionality turned out to be easy to impliment on the APD units wouldnt it be worthwhile?

Steve

RichardGreen

like wise


Richard

Ivon

Totally agree, if your not prepared to do your checks don't get a unit...simple as that.

A pre-breathe is part of the checks and a big part, may save your ass.

dave t

Guys, you can run this around and around and at the end of the day wet switches MAY have saved some lives but I bet A pound to a penny it would have taken some others, the more electronic hand holding we get the more complacent we may become. Its very intresting to note that as Phi said there have been no accidents on the kiss, why! because its the best rebreather in the world!! I dont think so, but a simple system focuses the divers mind a lot better than one that does everything except make the tea!

Its very easy to say "just do your pre-dives and it will be fine" but it wont because we will get complacent and the more the breather does for you the more the possibility of complacency.

Alex and his ORB project as an example scares the shit out of me (Im not having a go at you Alex) the more foolproof you make the breather, the more complacency will set in!

ECCR's can be made simple as well, with some careful design they can be as non complacency inducing as the kiss style breathers.

but nothing will ever stop it completly (except not diving!)

I vote no to wet switches

just my opinion

Dave

narked at 90

I vote auto turn on,
i cant stand the nanny culture and all the crap that goes with it.
but having an auto screaming "you cant dive because your a frigging Muppet" alarm is a simple addition that would have saved a lot of life's.
i totally agree, you need to take responsibly for your own actions and i much prefer diving kiss systems over eccr as you stay on top of whats really important.... but even the kiss system can fail by the user turning off the o2 supply so not to waist o2 after fcuk ups getting on shoots.
i try to be religious in my approach to setting up my breathers as possible and i get very narked when people interfere midway through but still some times things get missed, and even if you totally remove the **** wit factor accidents will happen.
but a simple twat alarm and Maintain min ppo2 can only be a plus in my book.
kind regards john routley
www.narkedat90.co.uk

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01RMB

From a recollection of a presentation nearly two years ago from APD I thought that the Vision electronics would turn on once under a couple of metres (pressure switch) and would try to maintain a setpoint of 0.21 with a low PO2 alarm of 0.16. The only reference I can find in the manual is if you started the start up sequence it would do this so I can’t be sure that it would be the same case if you had not even started the power up. Maybe a undisclosed design feature?? Someone would need to take a Vision for a dive without it being turned on to confirm!!

I had thought the idea was that the unit would sustain life (if the O2 was turned on) but not be very good for a dive. The buzzer and flashing red LEDs would warn you if the PO2 became life threatening. I think this is a pretty good compromise to taking care of people’s failure to turn on the electronics but the diver would still need to be aware that something was wrong and do something about it and it would still be a problem if you did a surface swim without turning the unit on.

Without speaking for APD, my understanding from Martin Parker was very clear that he did not believe in wet switches since although units which were off had caused deaths he did not want people to presume that the unit would take care of them throughout a dive if they did not follow a basic pre dive procedure. If you neglected to turn on the electronics then turning on the O2 was also likely. As has been mentioned in a number of other posts and I totally agree, this view appeared to be aimed at stopping divers from becoming complacent and neglecting to do their predive properly. Interestingly, Gordon Smith made the comment that he also agreed.

I have seen so many people jump in the water with their OC tanks off and their heads back on shore. With OC you will know pretty quick that something is wrong - with a Rebreather you won't even know you are dead.

I have never confirmed that the Vision would turn on automatically since I try to follow the “always know thy PO2” rule and you can’t do that when there are no lights in the HUD and the handset is blank.

As part of my predive ritual, before getting into the water I will give a big suck in to confirm the ADV fires whilst watching the PO2 drop from the set point of 0.7 and then watch it stabilise back when the O2 is added. If this is fine I know the ADV works, O2 sensors are working (within limits), controller works, solenoid works and displays are working.

Complacency kills – vigilance is required to stay alive.

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Cheers
Rod

heyydude

"Complacency Kills" is very true.

That is why all of our HH rigs come with Wet Switches.

Just....In....Case.....

I know AT LEAST 5 divers who are alive today because of our safety system(s).

That alone trumps any inconvenience they may have caused.


But then again, you all knew I'd say that...

Kevin Juergensen
Juergensen Marine, Inc.

sensor330

I voted yes. The only reason why is s#!t happens, we are all human and due to popular belief, we do make them on life support equipment as well. Yes I do agree it is the divers responsibility to do the checks and I do mine religiously. Losing ones life just because your unit is off seems senseless, especially if you did turn it on and for some reason it got turn off.

Simon A

If it's easy to implement then I'd say yes.
However I would vote that if possible it should turn on in a life supporting but non diveable way. Maybe for an eccr something like a continuous alarm, no ppo2 readings on the handset and continious oxygen addition. That way it's life supporting but too buoyant to dive?
Smon A

Mark Chase

My unit has both wet switches and a pressure switch to turn it on once you hit the water.

So what does it do? it turns its self OFF during the prebreath because its dry and not under pressure.

It's very frustrating.

Owing to the nature of our diving we are often kitted up and ready to go with 15min or more to wait before we go. Short slack windows and great depth means we have to get all the teems in quickly.

So I will often be prebreathing the unit for 15mins before i stand up and go diving. In the first 5 i will be carefully monitoring cell performance but then I prefer to go all Zen like and visualize the dive and the dive plan.

Quite often when I get the standby call i look down to find the units switched off again

Then there is the problem of not being able to switch the unit off in the water. If the solenoid goes spazo I cant just hit the off button on my hand sets and fly the unit on the back up system. If the units wet and underwater it's on. You have no choice.

Back when i had a classic I remember thinking if i had a solenoid jam on first thing I would do is switch off both hand sets. I had the VR3 plumbed in to check PP02 on my forth cell so i wouldn't be blind and i thought it would be quicker than isolating the 02.

I have wondered about incidents where divers have died and they found the unit switched off. If they got the unit switched off and then turned off the 02at a more leisurely pace if they were to tox at that point would the coroner be able to tell what happened?

Much as i love my HH controllers I have to say I don't see the safety features of a pressure sensor and wet switch as anything more than an irritation and i reeeeeeellllyyy wish it had a hard OF switch on the primary controller.

Leave the passive secondary with a wet switch so the HUD can tell me i am a dick head but give me a way to switch off when things go wrong.


Sadly the fatality reports speak for themselves (Unless my conspiracy theory is correct) so its hard / imposable to get Kevin to change his design.

ATB

Mark Chase

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See my "Doing It Chasey" video where I'm locked into a padded room, naked, with two ball bearings and within an Hour, I manage to lose one and break the other!!!

Kevin Juergensen 16/11/08
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