Fiona Sharp death in Bonaire

[Ayisha]

I agree that hand signals to communicate PO2 when necessary is a good idea. But I think that having your buddy actually monitor your PO2 within the breathable range is not relevant. Assuming that we are talking about two certified rebreather divers, expecting a buddy to actually monitor another diver's PO2 throughout the dive is not reasonable.

Unless you are talking about an instructor watching another student's PO2, the only thing that a "buddy light" needs to do is to alert a buddy that the diver is getting an alert (i.e out of the preset range of breathable PO2). So your buddy doesn't need to read the Smither's code and figure out what your PO2 is. They just need to be alerted that YOU are getting an alert. Then they need to confirm that you are appropriately responsive and have seen the alert. That's the idea behind - for example - the buddy light on the Meg or the JJ HUD:

View attachment 545937

That's what my buddy and I saw on a Meg rb diver during a shallow pumpkin carving dive about 6 years ago. Two pairs of very experienced rb divers had split up slightly into a line, each carving their pumpkins. My buddy and I knew the four of them, so we were hovering nearby observing their creations.

Out of the corner of my eye I saw one diver's HUD that was blinking green started blinking differently and then yellow and then very quickly red. He didn't seem to be doing anything about it and continued trying to carve his pumpkin. My buddy and I looked at each other and started moving closer to him, looking at him quizzically, concerned that he might go unconscious. We assumed he was probably going hypoxic since the max depth was 30 feet. I believe they had done a deep tech dive that morning with likely a hypoxic trimix.

Suddenly he took care of it and his HUD started blinking green again. We stayed close by for a while in case he had some delayed reaction or got behind on his gas management again, unbeknownst by his buddy, who was also busy carving a pumpkin on a seemingly innocuous dive.

I found the Meg HUD lights very easy to see and interpret, not having known much about them prior to observing them change.

 

[FreeFlyFreak]

Watching the thread closely.
I dislike seeing so much speculation so early without facts.

Reminds me of aviation accident speculation.

Find out the facts then learn lessons. Speculation helps no one.

RIP Fiona.

 

[fsardone]

Watching the thread closely.
I dislike seeing so much speculation so early without facts.

Reminds me of aviation accident speculation.

Find out the facts then learn lessons. Speculation helps no one.

RIP Fiona.

I respectfully disagree with you.

1. This is none like an aviation accident. The field is heavily regulated, the planning is recorded and a formal risk assessment is done and left on record. The supervisor will assess that risk and endorse planning and execution. Once the accident happens all of this is analysed and conclusions are drawn, procedures are changed and fleets are ground until remedial action is in place. Here, based on experience, all of the available data are, presumably, already known thanks to @tursiops that was there. The missing data (autopsy and computer download) unless the family or a court case (very unlikely here) will allow will never be known.

2. Speculation helps others rationalising what happened (see earlier @The Chairman post) and also explains the possible dynamic and reason of the accident. Also helps identifying the possible human failure in the decision making process that lead to the accident. Speculation is the realm of the possible based on the available information and, therefore, the "must avoid" pitfalls that might lead to similar outcome.

I am responding to you because in this thread I have been one of the most active "speculators". The main reason is I feel for her for her family even if I have no direct connection or knowledge of her. The dive she perished is the kind of dives I do weekly. The planning choices she did are the one I do (and as myself many of the contributors here) so her sudden demise is deeply touching. I believe all is within TOS of the forum. Feel free to report.

The only thing I agree with you is: may she rest in peace.

 

[KenGordon]

Out of curiosity, if you have a buddy and suffer from a too high or too low PPO2 on a rebreather, what could your buddy do to save your life ? Only to bring you to the surface ?

If you started drowning, it’s not very likely to bring you back alive, isn’t it ?

Watch out for the next time we run ST6, which might be this year. If I am teaching it I sometimes bring along my JJ and show the operation of the BOV and the red led which indicates a ppO2 out of bounds and explain the circumstances when action might be required.

Other options include flushing with dil, assuming a loss of dil isn’t the cause of the issue, or adding o2 if there is any left. However, diagnosing and responding to such failures is a large part of the training to use a rebreather so an OC buddy can’t be expected to be able to do it.

 

[The Chairman]

Suddenly he took care of it and his HUD started blinking green again.

Sensors are always a bit laggy. Once I make an adjustment, it takes a few seconds for the gauges to respond. There are things I can do to raise my PPO2 without touching my unit and you might not even realize I've taken care of the situation. Something as simple as exhaling through my nose can reduce PPO2, but it takes a bit of time. Practice and experience have taught me not to over compensate so I have to continually adjust my PPO2. However, I hate those lights and prefer to use two Shearwater handsets. I would love to have a NERD, but alas I can't afford it at this point.

 

[Peter69_56]

You could breath down a loop on a long gradual swim.
If the plan is true/accurate, I would honestly consider suicide as a possible initiating cause. "Happy" people can be in pain inside too.

As I dont know the Inspiration CCR and how it operates? Perhaps someone could enlighten me on the difference to a REVO?

Does the Inspo have 3 cells? Is it hybrid or manual or fully auto?

Is the canister a single one or two separate ones?

 

[Wookie]

Inspo has 3 cells. It was the first modern automatic rebreather with a setpoint controller. It has a single 8 lb scrubber that can be upgraded to an 11 lb IIRC. Known around the dive sites as a YBD, it’s marketed by AP diving, or Ambient Pressure Diving. Martin Parker is the developer.

 

[Dan]

I respectfully disagree with you.

1. This is none like an aviation accident. The field is heavily regulated, the planning is recorded and a formal risk assessment is done and left on record. The supervisor will assess that risk and endorse planning and execution. Once the accident happens all of this is analysed and conclusions are drawn, procedures are changed and fleets are ground until remedial action is in place. Here, based on experience, all of the available data are, presumably, already known thanks to @tursiops that was there. The missing data (autopsy and computer download) unless the family or a court case (very unlikely here) will allow will never be known.

2. Speculation helps others rationalising what happened (see earlier @The Chairman post) and also explains the possible dynamic and reason of the accident. Also helps identifying the possible human failure in the decision making process that lead to the accident. Speculation is the realm of the possible based on the available information and, therefore, the "must avoid" pitfalls that might lead to similar outcome.

I am responding to you because in this thread I have been one of the most active "speculators". The main reason is I feel for her for her family even if I have no direct connection or knowledge of her. The dive she perished is the kind of dives I do weekly. The planning choices she did are the one I do (and as myself many of the contributors here) so her sudden demise is deeply touching. I believe all is within TOS of the forum. Feel free to report.

The only thing I agree with you is: may she rest in peace.

You are a pilot & CCR diver. So, a question for you. To become a pilot, you do some flight simulations before actually doing the flight training. Is there similar diving simulation training to become CCR diver, such as entering your breathing rate, dive plan (depth & bottom time), number and sizes of bailout bottles, gas composition in the bailout bottles, different failure scenarios, etc.?

 

[Peter69_56]

You are a pilot & CCR diver. So, a question for you. To become a pilot, you do some flight simulations before actually doing the flight training. Is there similar diving simulation training to become CCR diver, such as entering your breathing rate, dive plan (depth & bottom time), number and sizes of bailout bottles, gas composition in the bailout bottles, different failure scenarios, etc.?

I think thats called dive planning. Thats all covered before you start using a breather. What happens if you have wrong mix, what combinations of gas are right and why, what happens if you have wrong mixes etc etc.

 

[Peter69_56]

Inspo has 3 cells. It was the first modern automatic rebreather with a setpoint controller. It has a single 8 lb scrubber that can be upgraded to an 11 lb IIRC. Known around the dive sites as a YBD, it’s marketed by AP diving, or Ambient Pressure Diving. Martin Parker is the developer.

I wonder why most re-breathers only have 3 cells? Cost?
Mine runs 5 cells, 3 into the controller, 2 into a Nerd, that's true redundancy. I personally don't like the 3 cell only rigs (not the rigs themselves as such, but the logic of only 3 cells and piggybacking off two of them for the backup). With a 5 cell unit, You can lose 2 cells and its still a div-able rig.

I also like split canisters so even if one breaks through the sorb due to poor packing, the other should pick it up so minimising the risk of a CO2 hit. Maybe its just me but I do like redundancy, particularly with re-breathers. I can lose the controller and still stay on the loop by driving it manually and using the Nerd. I can lose the solenoid and stay on the loop and drive it manually. Controller battery goes flat, drive it manually.

The only thing not truly backed up is operator error (although if its in auto it should try and keep you alive, which is a good thing but it wont save one from stupidity)