OP
Blackout. Currents. Rebreather
- Thread starter northernone
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OP
My thick head may need a few extra days to have the take aways sink in.
The rebreather dives since that night have been skills practice. Sticking to the shallows running BO drills, loop recoveries, SCR and managing offboard o2 and dill switches.
Also working on task loading managing the o2 breather. I don't think I'll bring it along on real dives for a while in the future.
Continued observations welcome. Might as well milk the miss best we can.
Regards,
Cameron
underwaterin your course did they teach offboard and dill switches ? as they should not or teach deco until you have the number of hours (unit specific) according to naui standards (tdi of course too )
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OP
While unrelated to the incident, I'll answer your questions. No, my knowledge of how to operate a lp QD came from a childhood introduction to using my parents new fancy bcds without the co2 cartridge and teen years working with air tools.
As a self trained homebuilder (risking another public stigma) I tend to want to use the tools available and offboad o2 makes sense for redundancy, wish I had it the day of the rip current.
Regards,
Cameron
Ps. To those interested, I did do my ccr certs afterwards as eventually I'd like to be able to teach once I have enough experience to be worth sharing.
P.p.s. Is there a bail out breather certification course available from any agency?
As a self trained homebuilder (risking another public stigma) I tend to want to use the tools available and offboad o2 makes sense for redundancy, wish I had it the day of the rip current.
Regards,
Cameron
Ps. To those interested, I did do my ccr certs afterwards as eventually I'd like to be able to teach once I have enough experience to be worth sharing.
P.p.s. Is there a bail out breather certification course available from any agency?
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OP
1. I'm glad I carried adequate bailout including the margin that I did have.
2. I realized I never CALLED the dive even though I thought I had. I TURNED the dive and began making my way to the exit (as a cave diver) but I didn't abort the dive and surface! It would have been inconvenient, meant a rescue, or long swim, worried people on shore and I'd probably have been hungry. However, instead of incurring deco waiting out the current art 90ft, I could have simply directly surfaced after I was free of the down welling, the same goes again at 35ft once deco was cleared.
3. Task loading. Running manual scr, navigation at night, in a current is no time to be trying to recover a flooded bailout rebreather. Especially when the surface is directly 35 ft above.
4. Don't hold my breath!!! CO2 buildup can result in overbreathing a scrubber.
5. Carry far more o2 and dill then the dive requires.
I'm just back from diving the same site, profile and gear configuration. This time with full o2 and dill. In daylight the surface is so close and inviting. The whole situation could have been avoided by simply calling the dive.
Other take aways or things of value we can learn from this situation?
Thank you for reading,
Cameron
2. I realized I never CALLED the dive even though I thought I had. I TURNED the dive and began making my way to the exit (as a cave diver) but I didn't abort the dive and surface! It would have been inconvenient, meant a rescue, or long swim, worried people on shore and I'd probably have been hungry. However, instead of incurring deco waiting out the current art 90ft, I could have simply directly surfaced after I was free of the down welling, the same goes again at 35ft once deco was cleared.
3. Task loading. Running manual scr, navigation at night, in a current is no time to be trying to recover a flooded bailout rebreather. Especially when the surface is directly 35 ft above.
4. Don't hold my breath!!! CO2 buildup can result in overbreathing a scrubber.
5. Carry far more o2 and dill then the dive requires.
I'm just back from diving the same site, profile and gear configuration. This time with full o2 and dill. In daylight the surface is so close and inviting. The whole situation could have been avoided by simply calling the dive.
Other take aways or things of value we can learn from this situation?
Thank you for reading,
Cameron
Thank you for sharing! Hopefully it was a valuable learning tool for all who read it!
MichaelMc
Working toward Cenotes
At risk of being MacGyverish, I've thought about options for returning to the surface slowly from depth in the event of a BC fail, from a hard bottom, in my very thick wetsuit. One option seemed ditching some weights but tied to the line of my SMB spool, 'anchoring' me and allowing a controlled end to a swim up. (In the absence of a dry suit and finding you were not as balanced as you thought.) In still water it seems like a reasonable backup contingency. In current?? I'm not so sure.
You've got a lot of experience. It seemed your problem was to not get blown to sea during deco, or after. Would tying off to the bottom, and reeling yourself out upward like a balloon in the wind have been a good option, or a crazy idea? It would seem to depend at least on the current, the bottom, and how much lift you would have to anchor against.
You've got a lot of experience. It seemed your problem was to not get blown to sea during deco, or after. Would tying off to the bottom, and reeling yourself out upward like a balloon in the wind have been a good option, or a crazy idea? It would seem to depend at least on the current, the bottom, and how much lift you would have to anchor against.
OP
Love the idea. Not quite SOP but sounds like a good tool to keep in mind. A reef hook or tie off to rubble perhaps, I don't carry enough detachable weights in warm water to be a viable anchor.
I have a friend who tied himself to a wreck and ascended using a reverse down line. Something to do with lost weights, I don't recall how he ended up that way exactly.
I like your thinking,
Cameron
Is your BOB a homebuild too? If you're married to the idea of a BOB I would recommend going with an already engineered independent solution, as it seems your current BOb may not possess the necessary flood tolerance required. Something like a KISS Sidekick or SF2 using spheres or small 1L steels make a great, fully self-contained BOB that is pretty flood tolerant, seemingly one of the major contributors to your incident. Worth a look anyway.
You might also consider changing to a "PSCR" style of configuration where you run linked twins as bailout, with another smaller O2 bottle plumbed into the rebreather. Because it's already being plumbed from an external source, provided your loop isn't compromised, you have other available options for gas addition. Since you're solo diving your level of conservatism and redundancy needs to be greater than even an individual bailout plan with a buddy. Put a BOV on the loop if your primary rebreather so you've got time to sort yourself before jumping to the BOB.
Glad you're still around!
You might also consider changing to a "PSCR" style of configuration where you run linked twins as bailout, with another smaller O2 bottle plumbed into the rebreather. Because it's already being plumbed from an external source, provided your loop isn't compromised, you have other available options for gas addition. Since you're solo diving your level of conservatism and redundancy needs to be greater than even an individual bailout plan with a buddy. Put a BOV on the loop if your primary rebreather so you've got time to sort yourself before jumping to the BOB.
Glad you're still around!
EricTheDood
Contributor
Do experienced CCR divers regularly switch between CCR and OC for technical dives? Or do CCR divers naturally resist switching back to OC except for rec dives?
The conditions of this dive would seem to have favored the OC diver or CCR diver with scooter. In hindsight, of course.
The conditions of this dive would seem to have favored the OC diver or CCR diver with scooter. In hindsight, of course.
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