Diver missing on Oriskany 10/22/11

[jhayes75]

Heard he didn't top off his dil bottle after Friday's dives and it was empty. also, if he was found 30' off the screws his dive plan changed. I don't think he would have been carried to the screws with Saturday's current.

It is possible that the diver never made it to the wreck. He could of went to sleep on his descent and slowly drifted to the location where he was found. Based on the following comment we can assume no one saw him enter or exit the wreck. Once his computer is analyzed it could tell us if he deviated from his dive plan.

Once on site we tied off, and another dive boat (the tech charter mentioned above) tied off on our line. We got into the water with our class, descended to the top of the superstructure, and conducted our exercises. I did not observe the diver at any point from the time we descended to the time we climbed back on the boat.

 

[Dive-aholic]

Rob

Not topping off the Dil tank is not necessarily a problem as the standard protocol is to carry enough OC bailout gas (plus some additional reserve) to get back to the surface from the worst possible point in the dive having completed all required deco stops. An experienced CCR diver only uses a few cu ft of Dil gas during a 2 hour deco dive with a square profile normally seen on a wreck dive. The Dil tank being empty could be a indication of some of the issues encountered during the dive depending upon what his configuration was and how much other gas he was carrying. Until additional information comes out on the state of the other tanks and his gear it would be difficult to narrow down the accident causes to a few logical number.

True. I didn't mean to imply anything other than the dil bottle had already been used on previous dives and was found empty. Take from it what you will.

 

[CheddarChick]

How incredibly sad for the family..But better than never knowing....:depressed:

 

[truleejulie]

My husband and I were part of the group. WhitewaterMike explained it superbly.

 

[bobthegoalie]

I am not familiar with the KISS rebreather but on most ccr's you can plug in offboard gases aka your bailout. Also you can be at the deepest part of your dive and be completely out of dil and get to the surface with no problem as you do not use dil on your ascent. You just lose the ability to do a dil flush which is a way to fix a problem for those who are not familiar with CCR procedures.

 

[Wookie]

This smacks slightly of Terry Dewolf's fatality on the Doria some 3 years ago. Terry jumped off the boat alone and his hip dump was hung open on his wing. He dirt darted in when he blew his dil bottle empty through his wing. Terry was not a novice rebreather diver, although he didn't have a lot of drysuit experience. If he did he might have inflated his drysuit instead of trying to inflate his wing.

 

[jkaterenchuk]

I am not familiar with the KISS rebreather but on most ccr's you can plug in offboard gases aka your bailout.

The Sport Kiss that someone earlier mentioned the diver was using does not come with off board gas connection as standard. However, it can be easily added.

Also you can be at the deepest part of your dive and be completely out of dil and get to the surface with no problem as you do not use dil on your ascent. You just lose the ability to do a dil flush which is a way to fix a problem for those who are not familiar with CCR procedures.

Except of course if your also using your Dil for wing and/or drysuit bouyancy control or if you have a BOV (Bailout Valve) which comes on the Kiss as standard and you had a CO2 hit because the scrubber brokethru as a result of diving deeper then the manufacturer recommends or overexerting during the dive or over extending the scrubber material duration. Or if your O2 cells were current limited and you were feeling somewhat strange and decided to switch to your Dil via the BOV to see if the feelings went away. Or your oriface was flowing O2 faster then you were metabolically using it at depth and you needed to bring the PO2 down by constantly injecting Dil. Then you could use up the small amount of a DIL in the (13cu ft or 19 cu ft) tank very quickly at 225fsw.

Not saying any of these apply to this situation since we know nothing about the dive configuration and gas and tank quantities. But they would be a common set of events which are possible when diving a CCR. There are also many more that might equally apply and result in a situation that was not recognized and then recoverable.

John

 

[Thalassamania]

... and you've just begun to describe the possible problems and failures.

That's why the Navy guy who taught me to use my MK-15 stressed that if no one was looking for your bubbles and wanted to shoot you, then, in a nut shell, when something went wrong with your rig, anything at all went wrong with your rig, you thought there was a problem with your rig: you go to your bail out and thumb the dive. Sometimes, you sort it out, and go back to your dive, but for now you are absolutely, clearly, definitively, in bail-out mode.

 

[bobthegoalie]

The Sport Kiss that someone earlier mentioned the diver was using does not come with off board gas connection as standard. However, it can be easily added.

Thanks for the clarification. I did not know that.

Except of course if your also using your Dil for wing and/or drysuit bouyancy control

If you do not descend any further these also will not need dil to be added. Now for the bov yes that can connect to the onboard but also can be routed to your offboard. All personal preference.

 

[Jax]

Thanks, John and Thal, for helping us to understand some of the 'what ifs'.