Buddy OOA in Challenging Conditions

[dumpsterDiver]

The OP's biggest errors were not to check on the buddy's air during the dive. I may not watch my buddy's air that carefully, but I definitely want to know when they are at 1500 psi.

getting hit in the head by the boat was also a potentially fatal error. The front of a big boat when anchored in a current is a huge hazard.

 

[PSFlyer]

No, I don't know how to figure out on the fly how long the pony would last another diver.

It is actually pretty simple. For most divers a typical SAC rate would be about .5 to .75 cu ft per minute. What I would use for emergency - is about 1.0 and I think of it as SSAC - Stressed Surface Air Consumption. Now be careful - these are surface numbers so you have to calculate them properly for the actual depth.

Example: A stressed diver would use up your 13 cu ft pony in 13 minutes at the surface which converts to 6.5 minutes at 33 feet (2ATA), 3.25 minutes at 66ft (3ATA) and so on. These numbers are a reference I use, now you have to do some additional simple math and use your ascent time from any given depth, include a safety stop, average the depths during ascent and... You guessed it - that 13 cu ft Pony looks VERY SMALL all of a sudden - doesn't it?

My hat goes off to you - you did the best you could at that time and you learned from it. You also had the guts to share the story so we could all learn. Happy Diving

 

[Bubbletrubble]

No, I don't know how to figure out on the fly how long the pony would last another diver. If I had, I guess I would have known if we had time for the safety stop. I was continuously checking my gauge, concerned that I might have to donate air from my main tank. When we were planning the dive, I said I would donate my primary reg, but in the situation it was easier to donate my pony reg. I think Trish was properly weighted, but I don't know for sure. As to your first question, I'm embarrassed to say that I didn't do any calculations to determine it. It just seemed like a conservative estimate.

@Beiji: I think it would be good to read NWGratefulDiver's gas management essay. Unfortunately, PADI and other instructional agencies don't cover this topic at all in either basic OW class or AOW class.

Just to do a recap on Trish's situation...
She was OOG (empty back gas + some gas in pony?) on the surface with an empty BCD and having problems remaining at the surface.
Since she had been using the pony, let's say that the AL13 was at most 1 lb. negatively buoyant.
Was she wearing a wetsuit? A full 3mm perhaps?
That would have provided a little more positive buoyancy at the surface.
And this doesn't take into consideration any extra air inside her lungs (over and above her lung volume at the time of her most recent weight check).
Perhaps she was slightly overweighted. Perhaps it was really choppy at the surface. Perhaps she was holding onto a lot of those medallions. Maybe it was a combination of those three factors. At least that's what I'm thinking...

On a related note, I'll quite often orally inflate my wing upon surfacing. Good practice for when power inflation isn't an option.

 

[fdog]

Lynne, I took a look at the thread you referenced. There must be something wrong with me, because I prioritize completely differently, as follows:

1. Team
2. Air
3. Light

Given that, I thought Lisa did well. She kept the team together (so she was actually around to help out with the OOA), managed Air (projected into the future & prepared to donate). The rest is experience gained, which will help with judgement in the future.


All the best, James

 

[Peter Guy]

James, isn't "air" always first? (And by "air" I'm assuming you are meaning gas -- if not, then what?)

Being OOA is the only true emergency -- despite what some on SB might think!

Now Air and Team may be totally intertwined -- but without Air, the team is useless.

 

[Beiji]

The OP's biggest errors were not to check on the buddy's air during the dive. I may not watch my buddy's air that carefully, but I definitely want to know when they are at 1500 psi.

getting hit in the head by the boat was also a potentially fatal error. The front of a big boat when anchored in a current is a huge hazard.

Agreed. I had no idea we would be in the situation we were in. I thought Trish was okay until we were at the line and I saw her gauge. It goes back to what I said about my tendency to assume that I'm the less experienced, less skilled diver.

You guessed it - that 13 cu ft Pony looks VERY SMALL all of a sudden - doesn't it?

My hat goes off to you - you did the best you could at that time and you learned from it. You also had the guts to share the story so we could all learn. Happy Diving

Thanks, PS. It's easy to share the story; it was hard to have the experience.

Yes, the 13 does look small. Well, it has always looked small, and that's why some of my buddies call it my "puny bottle." But now that I've used it for an OOA emergency I need to rethink the size. I hate to add more weight to my set up. As it is, I'm getting to the point where I sometimes need help hauling myself out of the water. I wish I could be self-sufficient on the boat and in the water, but as I get older, I suspect I will need more and more help. I probably need to do some strength training. I already do light weight training, but that's more to keep flab at bay than to build strength.

A diver I talked to the next day suggested that I add an inflator hose to the pony.

@Beiji: I think it would be good to read NWGratefulDiver's gas management essay. Unfortunately, PADI and other instructional agencies don't cover this topic at all in either basic OW class or AOW class.

Just to do a recap on Trish's situation...
1. She was OOG (empty back gas + some gas in pony?) on the surface with an empty BCD and having problems remaining at the surface.
2. Since she had been using the pony, let's say that the AL13 was at most 1 lb. negatively buoyant.
3. Was she wearing a wetsuit? A full 3mm perhaps?
That would have provided a little more positive buoyancy at the surface.
And this doesn't take into consideration any extra air inside her lungs (over and above her lung volume at the time of her most recent weight check).
4. Perhaps she was slightly overweighted. Perhaps it was really choppy at the surface. Perhaps she was holding onto a lot of those medallions. Maybe it was a combination of those three factors. At least that's what I'm thinking...

On a related note, I'll quite often orally inflate my wing upon surfacing. Good practice for when power inflation isn't an option.

Bubble, I numbered your questions/comments to make it easier for me to answer.

1 and 2. She had an AL 80 on her back. She was OOA around 60 feet. Once we were separated at the surface she did not have the pony bottle. I mount my pony using a bracket on the tank strap of my BC. She could have taken it off, but we hadn't discussed it prior to the dive.

3. I think she was wearing a 5mm with a hooded vest.

4. It was a little choppy at the surface, and there was current. She was holding onto only 3 or 4 medallions and one fin that had come off. She didn't have a snorkel on but has started wearing one since then.

Thanks for the link. I'll read it.

Given that, I thought Lisa did well. She kept the team together (so she was actually around to help out with the OOA), managed Air (projected into the future & prepared to donate). The rest is experience gained, which will help with judgement in the future.

Thanks, James.

 

[fast97rs]

ok.... You did a great job of keeping your cool Lisa! There are just a few things to consider.


1) if you don't understand what the diver meant when she wanted to head to the bow... stop her and ask. There is nothing wrong with making the person do the same signal a few times till you get it... (unless its the out of air... hahaha)

2) If a diver is low on their gas (and you only have a 13cu' tank to give)... give your octo to ascend. DECO STOPS are mandatory... saftey stops are NOT. Don't sit on the line... do a REAAAAAALLLY slow acent. When you get to 1000psi... either you switch to the pony or you hand it to the other diver. Don't let the diver EVER run out.

3) A pony with an inflator line goes a long way

4) You did right to stay on the line. The crew now can focus all their efforts on her rescue and not have to divide resources for you both... AND a tired diver tow can be done with the DM... but if both of you are blown off.... then how is she supposed to get both of you back to the boat?

5) She didn't require 02 and using it to treat a stress headache would remove that accet from someone else who might definitely require it.

6) On a new dive site... cheat and follow other divers... and ask people on the boat what their dive plan is. You have alot of resources on a boat : )

You did great!

 

[TSandM]

beiji, if you decide to use a bigger pony bottle (a 30 or 40) you can sling it like a stage bottle, in which case you can pass it up to the boat personnel before climbing the ladder. Makes life easier!

fast97rs, I really disagree with you about the OP being right to stay on the line. The other diver was completely out of gas, and ended up on the surface, rattled enough to be unable to remember to orally inflate her BC OR drop her weights. People drown that way. The boat did not have a dressed safety diver, and I think it was only luck that got someone to this lady before she went back underwater and didn't come up. I've read way too many descriptions of accidents that went that way.

If both divers are together, the boat has one place to send a pickup craft for rescue. It's not as though we are advising that two divers be floating around independent of one another. Keep hold of the OOA diver until she's on the ladder.

 

[ScubaQTX]

Wow, Lisa, I'm glad you and Tish are okay! Wish Derek and I had been there with you. (We know how much of an air hog you are!) jk. In my view, the most important thing is that you did not panic. I know that you were not taking risks because I know how you dive. You used that good head on your shoulders and got out with only a warning to never forget that this sport can throw you some curve balls. The thing is, you can never plan for every contingency. I'm glad to see that you got back on the horse. Now you know that you can deal with some adversity. You never know really until you get a scare like that. It will serve you well in the future.

 

[openmindOW]

When we got to the line she showed me her gauge - 300 psi. I pulled my pony regulator out of the elastic and held it and the line in my right hand, the hand next to Trish. I had to keep both hands on the line because the current was so strong. I was worried about Trish. She ran out of air around 60 feet, and I handed her the reg. We kept moving up the line, slowly and under control. I didn't know how long the 13 cf pony bottle would last for her.  

BEIJI, THANK YOU VERY MUCH FOR POSTING HERE AND FOR WRITING ABOUT YOUR EXPERIENCE IN A CLEAR, ARTICULATE MANNER.

BEIJI, you did fine. You stayed calm, you stayed with your buddy and you didn't panic.

You have learned a lot from the experience. You've been thinking about it and you've written about. That's great.

Current can be difficult. The current probably contributed to Trish's high air consumption. It's even possible that the current caused her safety second to do some free-flowing, although I don't know.

110' is a deep dive, and the current contributed to the diffuclty of the dive.

A 13 cubic foot pony does not provide much back-up gas for 100' dives.

A 30' bottle would be better. You can sling it. Heck, even a 19' cubic bottle would be better. One thing you might take away from this is that a 6' bottle or a SpareAir is probalbly not going to be enough back-up for a deep dive.

I'm also going to be a bit questioning regarding the general dive idea. 100' dives are serious. Personally, I'm not sure that it was very smart idea to hold a Treasure Hunt at that depth for recreational divers of uncertain experience. I don't want to critcize the idea, but I'm not sure that it was brilliant.

I would urge you to continue to dive. Please don't let this experience scare you out of diving in the future.