Wreck diver killed by leaking computer - UK

[rjack321]

Since he was at 6m for his deco, there was literally no danger or cost to bailout, isn’t it ?

(not saying that this was the cause of death, only running a hypothetical scenario)

He should have bailed on the bottom when the controller leaked. Hindsight 20/20 but you bring bailout and there is no reason to be on the CCR with a broken controller at all. It could have just as easily locked the solenoid open or some other issue. You don't have that much time to save your life with O2 wide open (at depth) or the solenoid shut off (shallow). Bail and fix it on the surface.

 

[Jack Hammer]

The Dive Forum

Relevant/related thread

I get an access denied message. I am a registered member there and logged in. Didn't see anything in the incidents forum

 

[Jack Hammer]

I have a JJ. Even if the controller flooded the HUD (blinky light thing by mask) operates independently and should still indicate the current PO2. This should safely allow flying the unit manually. O2 can be added without the solenoid working. There is no way for a flooded controller to flood the battery compartment in the head. There are wet contacts between the head and controller. Batteries are sealed. There are likely other factors.

 

[KevinNM]

Roughly yes, and sadly his buddies were not there.
Hard to imagine the need to stay on the loop at all that early in a wreck dive with no delay, entanglements etc on the bottom. Just bail out.

Teams are not just 3 people diving in the same vicinity. Yet another story of a guy who got sent off to surface by himself by his buddies and died after running into another problem by himself.

 

[Dusty123]

So rebreathers with divecan are supposed to operate at the low setpoint in the event of handset failure this was an earlier unit?

 

[telemonster]

If the handset floods, is there a possibility that the cable that leads to it could pass water down it? I know a friend's unit had a crack in the cable and he was getting water in the battery box of his unit.

On a Shearwater CANBus based unit, I would think that the handset passes the setpoint to the control board in the head. This is one of the two devices sampling the sensors in the head, and should maintain the setpoint without the handset? If this is the case it might be able to handle the controller being flooded. Can anyone confirm?

If water (especially salt water) is able to make it into the head (depending on the way the unit is laid out) it could possibly wipe out both the primary controller and the "read only" (HUD) controller's ability to sample the sensors.

Unfortunately it's not easy to find the architecture of how some of these are put together. My unit is a Hollis Prism 2 with the CANBus electronics and I had a small issue. No one would tell me details (my local dealer, Shearwater, etc.) So I had to open the "forbidden" box myself.

Earlier in the thread it was said there was power supply (dead battery) issues in the head so that sounds likely that salt water made it down the cable?

 

[rjack321]

So rebreathers with divecan are supposed to operate at the low setpoint in the event of handset failure this was an earlier unit?

I thought this was an earlier analog unit.

 

[rjack321]

I have a JJ. Even if the controller flooded the HUD (blinky light thing by mask) operates independently and should still indicate the current PO2. This should safely allow flying the unit manually. O2 can be added without the solenoid working. There is no way for a flooded controller to flood the battery compartment in the head. There are wet contacts between the head and controller. Batteries are sealed. There are likely other factors.

The most reliable way - bail and GTFO

 

[ScubaWithTurk]

Could he have controlled the unit manually and got to the surface safely? Yes he could have using the MAVs. However, this idea of "stay on the loop as long as possible" can become a dangerous one.

When we dive, all dives are planned with enough bailout to get to the surface from the deepest depth. Looking at this story, it seems he was at his 6m stop when things went breasts up. IMO, there is zero reason to stay on the loop at this point. Bailout, finish your stops and sort out the issues safely on the surface.

I will say that there are some dives where getting off the loop, sorting out an issue and getting back on it are ideal. Even staying on the loop and trouble shooting with dil or O2 flushes to sort things out. Yet this was not one of those dives and the "stay on the loop" mentality seems to have played a factor here.

This is sad to read and hopefully we can all learn something from this and dive our units safer.

 

[KenGordon]

It is worth reading the TDF thread.

Of note. Analogue JJ, water leaked into the handset, apparently it can run back up to the head and it sounds like it might have. He did 20 minutes at 6m before sinking.

My guess is that it seemed to be working so he stuck with it but eventually it wasn’t. Something to keep in mind, electronic failures can develop.

Later JJs, with CanBus, have a connector at the head end which prevents this.

My CanBus JJ handset was given a new screen arrangement, now there are no longer bolt holes through the glass, when my head was in for repairs late last year.