another question from manual
- Thread starter Frosty
- Start date
Please register or login
Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.
Benefits of registering include
- Ability to post and comment on topics and discussions.
- A Free photo gallery to share your dive photos with the world.
- You can make this box go away
Hello Frosty,
I believe you are discussing Case Study Six - Extremely Low Air. This case study deals with the actions of the DM leading a travel group of divers (of which the instructor was part of that travel group and no instructional activities are being performed).
The diver with low air already refused the DM's signal to ascend, so the DM shows the instructor the diver's SPG and signals that the diver has refused to ascend. The instructor takes hold of the diver and signals to ascend in a "very no-nonsense" manner. We later find out the diver was the instructor's past student, they both made the ascent, they skipped a safety stop, and they both get picked up by the boat without incident.
Since the case study is looking at the actions of the DM, it does not go into any detail about the ascent, the attitude of the diver during the ascent, or other items. It simply details that in this specific case, the DM decided that maybe the instructor with the group could convince one of his group members to ascend.
You are questioning the actions of the instructor and asking why he/she skipped the safety stop. This is a fair question because there may be a day when your are a DM and have to convince somebody to ascend immediately. The case study does not give details about what transpired during the ascent. What the diver did or did not do, etc. We only know the instructor made the decision to skip the safety stop and get to the surface. The ascent and actions taken or not taken was not part of the case study.
Others makes a very good point about level of risk...and it is something you will likely experience as you asist with classes and perform Scuba Review/Tune-up sessions or ReActivate sessions as a DM with certified divers. Never assume that alternate air sharing and ascent is a flawless operation. It is rarely practiced by the average OW diver. I have seen recreational divers put the regulator in upside down, breathe wet, and then try to bolt to the surface. An ascent directly to the surface was an option and I believe it has less risk than trying to get an already uncooperative diver to utilize and ascend with your alternate air source. Since we don't know anything about what actually transpired during the ascent with the instructor, it can be assumed he used his best judgment and decided skipping the safety stop and getting this diver back into the boat was the prudent action to take in this situation.
I believe you are discussing Case Study Six - Extremely Low Air. This case study deals with the actions of the DM leading a travel group of divers (of which the instructor was part of that travel group and no instructional activities are being performed).
The diver with low air already refused the DM's signal to ascend, so the DM shows the instructor the diver's SPG and signals that the diver has refused to ascend. The instructor takes hold of the diver and signals to ascend in a "very no-nonsense" manner. We later find out the diver was the instructor's past student, they both made the ascent, they skipped a safety stop, and they both get picked up by the boat without incident.
Since the case study is looking at the actions of the DM, it does not go into any detail about the ascent, the attitude of the diver during the ascent, or other items. It simply details that in this specific case, the DM decided that maybe the instructor with the group could convince one of his group members to ascend.
You are questioning the actions of the instructor and asking why he/she skipped the safety stop. This is a fair question because there may be a day when your are a DM and have to convince somebody to ascend immediately. The case study does not give details about what transpired during the ascent. What the diver did or did not do, etc. We only know the instructor made the decision to skip the safety stop and get to the surface. The ascent and actions taken or not taken was not part of the case study.
Others makes a very good point about level of risk...and it is something you will likely experience as you asist with classes and perform Scuba Review/Tune-up sessions or ReActivate sessions as a DM with certified divers. Never assume that alternate air sharing and ascent is a flawless operation. It is rarely practiced by the average OW diver. I have seen recreational divers put the regulator in upside down, breathe wet, and then try to bolt to the surface. An ascent directly to the surface was an option and I believe it has less risk than trying to get an already uncooperative diver to utilize and ascend with your alternate air source. Since we don't know anything about what actually transpired during the ascent with the instructor, it can be assumed he used his best judgment and decided skipping the safety stop and getting this diver back into the boat was the prudent action to take in this situation.
OP
YET AGAIN__thanks a million guys. Im not trying to reinvent the wheel of course. Just working through the logic.
Sevenrider-I get it now. What seems a perfectly logical and reasonable solution sitting here in front of the PC can quickly turn into a mare 25m under the sea.
Sevenrider-I get it now. What seems a perfectly logical and reasonable solution sitting here in front of the PC can quickly turn into a mare 25m under the sea.
I think sevenrider has gotten to the heart of the question. But I'm with you; if in that circumstance myself, I would attempt to get the low on air diver onto my gas supply for the ascent, and then perhaps put him back on his own for a safety stop. However, the comment is entirely right, that most people NEVER practice sharing gas once they are finished with their OW class, and the task loading involved can destroy their buoyancy control and even cause panic. We had a death here, the year I was certified, when a fairly experienced diver ran out of gas at depth, successfully initiated an air-share with her buddy, and then panicked during the ascent, jettisoned the regulator and bolted, and embolized. I don't think you can ever assume that the person you are helping has anything but the most basic diving skills, and the decision whether to donate gas early and avoid an out of gas scenario, or take the diver up in a presumably calm state, hoping to avoid sharing gas, is an on the spot decision that could depend a great deal on the instructor's knowledge of that particular diver.
500 psi on the gage can let you do a lot if needed , however if there is a gage error like 10 percent then the low on air diver may only have 2-300 psi. I would do a direct accent to the surface also. unhappy diver and low on air is fuel for panic. Stress is building. Id again go straight to the surface and keep the low on diver functioning in a breathing environment that he is now comfortable with and not inject air assist and create a low on air diver wondering what is going on initiating panic.
I would say this "Case Study" has done a great job...got the reader and SBers thinking...
OP
Again thanks folks.
in the scenario it took place in 80' of water. 500psi should be good for an ascent. Only takes less than 2 minutes to get to surface using a slow easy ascent ..why complicate in unnecessarily and try a alternate air ascent. Obviously a alternate air source should be held and ready to be used if needed. A "genuine out of air" does not happen immediately. By the time shallow (20') water is reached,even if person is down to 200psi there will be no issue on breathing easily all the rest of way to surface.
The only caveat I'll throw in there is that "breathing easily" can have both a physical and a psychological meaning. In the two situations that I've been in that were fairly similar to this case study... both LOA divers required my long hose in order to "breathe easily" from a psychological standpoint.
In neither case was I the diver's buddy, not working as DM/instructor, or even particularly known to them at the time of either incident. Neither found my looking at their SPG at the given depth and telling them "OK" to be particularly comforting. One kept shaking my signal off as if I were a pitcher repeatedly signalling a catcher that I was gonna throw A-Rod a slow hanging curve out over the plate, telling me afterward that he simply assumed I didn't understand that he was LOA. The other was clearly moments from panic and skip-breathing, telling me afterwards he was deathly afraid that each breath would be the last he'd get from his tank and that switching at that point would be an issue.
As always, you need to read the situation, the environment, and the diver before deciding the best course of action. Which is the point of the case study approach.
OP
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.
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.
Similar threads
