another question from manual

[RJP]

Just spitballing ideas here now folks. What if the Instructor wasn't there?
As the Dm leading what would you do given the same scenario and the diver concerned seemed to be belligerent to the DM?.
So every diver is responsible for themselves but you have a duty of care.
Im thinking theres gonna be 5 none too happy divers as you lead the whole group back up towards the safety stop/down line. waiting for the inevitable to happen.octi ready to be used and reorganise the divers so the belligerent one is right behind you.
-Working on the theory the low air diver will stick with the group even if they wont go up on their own.

You're the DM. What did you discuss in your briefing about signalling remaining gas, turn/ascent pressure, and procedure to end the dive? Therein lies your answer.

PS - the instructor being there (or not) is a bit of red herring, he's not there as an instructor anyway. If present and guiding he's a good warm body to take the LOA diver up leaving you to guide the rest of the dive.

PPS - what do you mean "no issue with air checks" in original post? Unless the LOA diver suddenly started sucking down his tank he must have gotten to half a tank in about 12min, which should have alerted you and the instructor to his air-hog status. One of you should have known then to bring the whole group shallower if possible. Either way, it goes back to the briefing... what did you tell the divers under your supervision about airchecks and turn/ascent pressures?

PPPS - it's a drift dive... there is no downline.

PPPPS - who was the LOA diver's buddy? What's he doing while the instructor ascends with LOA?

 

[C P]

Has anyone looked at their tables? Safety Stops are "required" for (1) any dive to 100 feet or deeper (I'm challenged in the metric conversion, sorry), (2) any dive to a No Decompression Limit and (3) for any dive within 3 pressure groups of a Decompression limit. 80 feet for 25 minutes doesn't fit into those rules. I'll agree a safety stop is always a good idea, but in the context of this question this is relevant and should be part of the discussion and I would think tips the scale in favor of a direct ascent to the surface and not sharing air. There are more layers to this question, and things you want your DM candidates to think about. As an instructor, especially with one of your prior students, this should mean there will be a prayer meeting with the diver about several points

 

[Jim Lapenta]

Actually safety stops are not required. They are very strongly suggested. Actual required stops are not safety stops they are decompression stops. If a stop is required you are no longer doing ndl dives.

 

[C P]

The quotations around required are because it is on the tables. Again look at the tables and understand the reason for the exercise and the context the question was posted.

 

[TSandM]

As already mentioned, this problem gets fixed much earlier on. If I'm the DM leading the group, then at 10 minutes into the dive, I'm going to ask each diver for his pressure. This will identify the people I need to watch, and they will be asked more frequently.

If I have failed to do this, and the diver has failed to notify me at the 1500 psi point that I briefed on the boat, then when I realize the person is dangerously low on air AND is refusing my signal to end the dive, I turn to the rest of the group, signal thumbs, grab the low on air diver, and start up.