If your buddy that had 350psi remaining at some unknown point...
Did he or anyone attempt to communicate this to the DM? The DM must have communicated in some fashion, "follow me". Did 350 just not get the signal out, a likely problem for a diver in that situation. Did you try to communicate that "alarming" status?
During our dive briefing, these words were said: "If you can't see your guide, you're lost. If you're lost, surface and look for the boat." So we were following the guide.
Grace ("350") was perhaps not doing an exemplary job of monitoring her SPG and communicating her situation to the guide. She is 14. Our instructions were to give the "turn" signal at 1500, which she had done. I did mention after the dive that she could perhaps do a better job monitoring her air and making sure the guide/DM/buddies are aware of her situation.
Were you ready to ascend right then with the 350 guy and display a SMB? You said conditions were calm, so you could have waited with him for the boat to come get you after other divers boarded.
I was. As I noted in the OP, I was on the verge of sharing air (my cylinder was at 1000 PSI), which seemed like the most practicable way to conclude the dive safely and without making a scene.
But 350 made it through that 5+ minute shallow swim, no small feat. Obviously not the best skill sets, hyper buoyant by then, shallow depths exacerbating buoyancy, under mental stress from staring at SPG, a fast pace.... I mean really, this 350 diver pulled a major rabbit out of the hat. The way you describe their situation, I would have seen 350 in an OOA and at least so bouyant that they went all corklike. Miraculous, actually.
She is a former competitive swimmer and is extremely comfortable in the water, and was largely nonplussed by the situation. She was maybe a little floaty but didn't seem to care.
If you don't feel it was a safety problem, what is the relevance of this story? The way you couch it, I am thinking you believe it was a safety issue, it may well have been. Dunno.
I was, at the time, processing it as a troubling situation that deserved close attention to avoid the possibility of it becoming an emergency.
You are a "solo diver", I assume this means you carry a completely redundant air supply beyond that 120cf tank you prefer. Were you ready to hand that redundant supply over to the 350 and let him continue underwater?
My kit varies situationally. On this dive I had a short-filled AL100 as I had used my HP120 on the previous dive on this trip. I did not have a redundant air supply, and I have not practiced stage bottle handoffs with these two. I would not attempt a stage handoff to an OOA diver who had not practiced it beforehand even if I had one. On this dive I was ready to hand over a primary reg on a 40" hose and breathe off my secondary. I was also ready to surface and sort out the problems there.
Do DMs get lost? Rarely. Depends on the DM and locale. What were his announced duties?
Navigation, and getting us back on the boat with 500 PSI and before 60 minutes was up.
No reason for you to rush after the DM leaving 350 behind. You could have easily noted his newly aquired heading and stayed at 15' depth with 350 instead of stretching the line of vision out so far. If all else fails, you could also blip to the surface, take a heading, then continue the march homeward.
Certainly a valid alternative.
Does this happen? All of those things? Yes, all the time.
Hmm.
In my guiding experience, it is relatively uncommon, but can be very site specific. Some sites are just really easy to get lost in and if you are depending on natural navigation only, you are going to get lost.
We were on Molasses Reef, near Key Largo, which I wouldn't consider particularly difficult to navigate as there are any number of major, unmistakable landmarks. I've only been on the reef 3 or 4 times and don't have the relationships between the landmarks memorized.
I believe our guide was trying to take us on a very slow circular path, instead of multiple out-and-backs or a single out-and-return. I didn't see him take any compass headings.
But realizing your mistake and sprinting back to the boat rather than do the surface swim of shame? That's not acceptable in my book, but still happens unfortunately.
+1
Without sounding too negative, the decision of the OP to position himself in the middle of the DM and the daughter because he was trying to avoid being "lost" was understandable but not the best decision. A failure to properly evaluate priorities. It was probably more important to maintain the buddy system and if the two end up lost (together) on a shallow anchor dive.. well that is embarrassing, but should not be dangerous if you have an smb and a captain is on the ball.
Not an "accident" but a good opportunity to think about how situations evolve toward an incident.
..nod.. It didn't help that we were diving as a threesome. I don't think the third diver realized what was going on. She was ahead closer to the DM, and was still good on air.
Though no one has mentioned it, one of my "take aways" from this sequence of events is that I am trying to pay closer attention to navigation when following a guide around.
