Full Face mask Cave diving.

[karstdvr]

What about an underwater air horn like some connect to their LPIs....may connect it to an argon bottle so not to expend breathing gas?

There used to be a device that would fit between the power inflator and hose that would emit a sound. I know some people that experimented with that, and really didn't serve a practical purpose. They experimented in a lights out situation to simulate zero viz, and basically they knew each other was in the vicinity ,but not a clue where each was. What they did find was they used their basic skills, and would find each other at the rally point they discussed, and ended up not using the devices. Cave divers are experimenters, that is why OW divers have power inflators, BCs etc, and the "air horn' device was attempted, and resides in the archives of cave diving.

 

[ofg-1]

I have tried cave diving with a FFM. I have owned both a KMB-9 and a Aquadyne DM5. One of my first cave instructors, Bob Axlerod, dove occasionally with a KMB-8. First, it limits your head mobility. You just cant look around as easily. Second, you do have an increase in gas consumption, the void space in the mask even with a oral nasal is greater than a regulator. Also, you are off trim with one, it is just not as comfortable. Where I see an advantage would be in some type of medical event that would cause the diver to spit out his regulator, or if you are decompressing on O2 and worried about a hit. Downside, if you have never puked in a band mask, it does take some readjustment of your thought process. Other than a curiosity, it has no other advantage that I can see. I know that rebreather divers can adapt their BOV to a Kirby KM48 supermask, there may be some benefit, but you would have to ask a rebreather guy.

 

[Yank]

FWIW, every time I see divers on a television "documentary", they get excited and yell into the coms of their FFM. Maybe it's just the usual dumb tv drama, but I can imagine a panicked diver screaming in the FFM. Not to mention some CO2 issues that can add to panic if you don't manage your FFM correctly. Also, OFG-1 is correct about air consumption and trim. I dove a KM 26 several times and it requires a different skill set than a regular scuba mask. You would also need a gas switch block for SM doubles, and this is more task loading. I'm not sure you could see your SM gauges easily in some FFM.

 

[Jack Hammer]

People who lack basic skills or are too lazy to take the time to learn and hone basic skills often look for overly complicated solutions as a shortcut and crutch to replace those skills.

 

[boulderjohn]

hen I agree with Ken, the additional few minutes gained in being able to verbally communicate is not beneficial versus the technical issues with a FFM and reduced ease of redundancy. If a dive has good planning from the start, then the need for communication is reduced during the dive to only unplanned situations.

I still don't understand this. As I said, they should have done a lot of things differently. There was a lot wrong with that dive from the start. However, I still don't see how being able to communicate at that critical moment would not have helped. You said it would have only saved a few minutes. I have no idea what you mean. The difference would not have been a few minutes gained--it would have changed the decision as to whether to leave the other diver and head for the exit or stay long enough to assist his exit. Towing him out with your scooter rather than leaving him to swim the entire way and possibly sharing air near the end is not the same thing as gaining a few minutes.

 

[Jack Hammer]

John, perhaps you should be asking yourself why the cave diving individuals and groups who use FFM's w/comms don't use them on every dive? Why do they only use them when the task requires it?

 

[Bennno]

I still don't understand this. As I said, they should have done a lot of things differently. There was a lot wrong with that dive from the start. However, I still don't see how being able to communicate at that critical moment would not have helped. You said it would have only saved a few minutes. I have no idea what you mean. The difference would not have been a few minutes gained--it would have changed the decision as to whether to leave the other diver and head for the exit or stay long enough to assist his exit. Towing him out with your scooter rather than leaving him to swim the entire way and possibly sharing air near the end is not the same thing as gaining a few minutes.

I don't know if that's what Ken meant but I would say you shouldn't try to fix bad planning or the lack there off by bringing extra gear. Would it have helped in that specific situation? Maybe, yes. But IMHO that doesn't lead me to the conclusion that a FFM would be useful in general... the problem was the dive plan, not the gear. More gas and cookies would have helped more than a FFM.
Besides, I find FFMs super uncomfortable and cumbersome. I wouldn't wanna use one unless I have to.

 

[Jack Hammer]

The difference would not have been a few minutes gained--it would have changed the decision as to whether to leave the other diver and head for the exit or stay long enough to assist his exit. Towing him out with your scooter rather than leaving him to swim the entire way and possibly sharing air near the end is not the same thing as gaining a few minutes.

You're assuming that if they had comms they would've have been charged /working. BTW, they were diving SM, FFM's would have made interesting gas switches and sharing... ☺

 

[boulderjohn]

There's a lot more to the first fatality and a full face mask would not have helped the situation.

John, perhaps you should be asking yourself why the cave diving individuals and groups who use FFM's w/comms don't use them on every dive? Why do they only use them when the task requires it?

But IMHO that doesn't lead me to the conclusion that a FFM would be useful in general...

BTW, they were diving SM, FFM's would have made interesting gas switches and sharing... ☺

I seem to be having trouble communicating the idea that I am talking about advantages in being able to communicate over a small distance during a dive and am not advocating the use of FFMs.

Notice that although the thread starts with the idea of full face masks with coms (which is the solution Bernie Chowdhury decied on for technical diving problems, BTW), I just said communication. There was another thread recently about a potential device that would transmit a simple buzz over moderate distances. I can see (with something along the lines of a morse code) as having some benefit.

I can think of two very recent fatalities and near fatality that might have been avoided if two divers had had the ability to communicate effectively over not too much of a distance.

I would like to point out that I mentioned several other incidents in which such communication would have been helpful, occasions that did not include the red herrings in the one incident people are focusing upon.

 

[kensuf]

I seem to be having trouble communicating the idea that I am talking about advantages in being able to communicate over a small distance during a dive and am not advocating the use of FFMs.

I would like to point out that I mentioned several other incidents in which such communication would have been helpful, occasions that did not include the red herrings in the one incident people are focusing upon.

I think you're not listening to what we're telling you, and maybe that's our fault.

The first and third incident you discussed have little to do with lack of tools or technology for communication and are simply failures to use the communication tools and skills they should have already developed.

Think back to your cavern class. You should have been taught there are four ways to communicate underwater in a cave. They are (in likely order of use):

1. Light signals (the primary method of communicating)
2. Illuminated hand signals
3. Touch contact
4. Written

The first and third incident should have been solved by touch contact communication. Even if you ascribe to the use of "bump and go," the first incident (and probably third) was a failure because you are supposed to re-connect every few feet and once you hit clear water re-connect again. And if you believe in continuous touch contact instead of bump and go, then the first and third incident were clearly failures in communication.

Does that help?