Out of air emergency at 105 feet

[paddler3d]

I would love to see the following poll on this topic.

A) Blow the safety stop and surface with the DM...the complete rescue methodology
B) Let the DM surface and you complete the safety stop...the bye-bye methodology

Decision is based upon the following: understanding that this had been after a few days of repetitive diving and this dive was relatively deep, knowing that the OOA diver was the DM, the paid professional, knowing that there was more then enough air for two divers to complete the safety stop, and then some, knowing that the OOA DM was the one who wanted to blow the safety stop.

 

[nuts4corals]

here's my computer dive log of the dive and ascend... I placed my cross hairs at 40 feet which is where the acsend started to pick up speed. you can see this from the information at the top of the graph.

 

[nuts4corals]

looking back at the graph thank goodness this happened at the begining of the dive.

 

[paddler3d]

Check out the link at the bottom of Lamont's signature, as well as NWGratefulDiver's Gas Management article. It takes a while to process, but you can actually learn this, along with the shorthand calculations to figure stuff out underwater. For instance, I rarely try to do the math nowadays, but I know with an AL80 diving to 100fsw, I know that a full-blown gas emergency at depth requires about 1,600 psi in order to make a safe air-share ascent (so I need to start moving shallower before I hit 1,600psi). Knowing this also affects my willingness and planning to do certain deep dive profiles on AL80s and other small cylinders!

Wouldn't the whole idea of the rule of 1/3's a lot more simplistic?

BTW how do you know or figure out the 1600psi thing on an AL 80? Did you do the math or was it a school of hard knocks lesson?

 

[nuts4corals]

I would love to see the following poll on this topic.

A) Blow the safety stop and surface with the DM...the complete rescue methodology
B) Let the DM surface and you complete the safety stop...the bye-bye methodology

Decision is based upon the following: understanding that this had been after a few days of repetitive diving and this dive was relatively deep, knowing that the OOA diver was the DM, the paid professional, knowing that there was more then enough air for two divers to complete the safety stop, and then some, knowing that the OOA DM was the one who wanted to blow the safety stop.

I would love to see the results of that... can you set that up?

 

[ScubaSteve]

How long did it take you to get from 40' to the surface? I am not sure if your computer will break it down into seconds or not. Mine (Cobra) is set and reads in 10 second intervals.

Also, how was the DM acting once they got on your Octo at depth and realized they had air? There was no reference to any real panic or anything so I assumed that they were very composed. However, if you told them you wanted to do a 3 minutes stop and they just kept going, perhaps not. Did they appear panicked?

 

[paddler3d]

I would love to see the results of that... can you set that up?

I was putting that out there because I have no idea how someone does those polls...:crash:

I think I picked the wording carefully!

 

[TSandM]

Just remember that safety stops are optional. Thalassamania will be happy to tell you that they were introduced to control ascent rates, but have persisted as standard practice. (There is some Doppler evidence that they do help to control bubbles as well.) In any situation in recreational diving where there is an urgent need to return to the surface, they can be safely omitted -- this is the ESSENCE of recreational diving, that a direct ascent is always an option. (This is, of course, assuming a controlled ascent rate.) Keeping a distressed diver underwater to do an optional stop is probably not the best strategy.

The people I dive with practice air-sharing and air-sharing ascents on a regular basis, in the hope that, should some major equipment failure leave someone out of gas, we CAN execute a calm ascent and do all our stops. (Our not-quite-NDLs are also figured based on a certain decompression procedure, so the stops aren't quite optional.) But most people don't practice these things. In addition, standard recreational setups can make it uncomfortable or awkward to hold stops while sharing gas, and shallow stops are often a challenge for less experienced divers. There are a lot of reasons to consider omitting any stops when escorting an OOG diver to the surface, and very few reasons to insist on completing them.

 

[Gombessa]

Wouldn't the whole idea of the rule of 1/3's a lot more simplistic?

It turns out this is commonly asked. But there are situations where simply relying on thirds leaves you with insufficient gas to get you and a buddy up to the surface. That's why most thirds calculations (especially for open water) are typically made ON TOP OF rock bottom calculations.

BTW how do you know or figure out the 1600psi thing on an AL 80? Did you do the math or was it a school of hard knocks lesson?

That's math-derived for actual time required at depth to sort out problems, ascent rate and SCR for myself and my most regular buddies; but it is pretty close to a "typical" RB profile with combined 2.0 SCR. A lot of OW divers have done a 100fsw dive on an AL80, without realizing how much gas they would need to air share to the surface, so I always see it as a particularly relevant example to share.

I'm very fortunate to say that I haven't yet suffered a real OOG situation on either side. I HAVE however, seen multiple OOGs on the above profile (in Hawaii and other resort locations) which resulted in someone breathing off the DM's octo during the ascent/safety stop. Imagine if you went OOG around one of these guys and found out he was about to go OOG as well!

 

[nuts4corals]

How long did it take you to get from 40' to the surface? I am not sure if your computer will break it down into seconds or not. Mine (Cobra) is set and reads in 10 second intervals.

Also, how was the DM acting once they got on your Octo at depth and realized they had air? There was no reference to any real panic or anything so I assumed that they were very composed. However, if you told them you wanted to do a 3 minutes stop and they just kept going, perhaps not. Did they appear panicked?

Let me put it to you this way... I can't get the guys wide open/ panicked eyes out of my head. interestingly I remember feeling as if he was composed at the start of the ascend as soon as he received air. but than at around 40 feet it was as if he wasn't purging his BCD or fining a bit quicker than befor. I'm not sure what was going through his mind but when he blew off the safety stop I think he may have been panicked... Hard to tell looking back on it. All i can tell you is that i was so calm that every second seemed like 5. BTW, my computer was set to calculate every 15 sec. on this dive and looking at the info. it took about 40 secs to reach the surface from 40 which seems fine to me but the computer does have 40-20 in red as ascending too quickly...