Thoughts on post roll-offs and first stage hose routing

[RTBDiver]

I think that if you were to ever find yourself as the OOG diver on a long hose exiting through a restriction your view point may change slightly.

For the record, I'm all for people using whatever gear configuration they're comfortable with. I'm just an advocate of them fully thinking through all the ramifications of their choices.

Please elaborate, Do you feel I would disagree with the fact I nor any buddies have ever had an issue with roll off while using metal knobs, Do you feel just where the hose is placed is what may change my views?
Don't just tell me my views would change without letting me know why. Maybe you can add some info so I would change the config before entering the next wormhole

 

[Cave Diver]

Please elaborate, Do you feel I would disagree with the fact I nor any buddies have ever had an issue with roll off while using metal knobs, Do you feel just where the hose is placed is what may change my views?
Don't just tell me my views would change without letting me know why. Maybe you can add some info so I would change the config before entering the next wormhole

I can't argue with you about what your experiences with metal knobs would be, because they are after all, your experiences. In my experience it's unusual for cave divers to dive doubles with metal knobs.

And I will agree with you that metal knobs are much harder to roll off by contact than plastic and rubber knobs.

My comment went to the fact that should you find yourself in a situation (metal knobs or not) where you were an out of air diver, breathing off someone's left post long hose and they experienced a roll off, then you might change your mind about the the effectiveness of one routing choice vs. another.

 

[RTBDiver]

I can't argue with you about what your experiences with metal knobs would be, because they are after all, your experiences. In my experience it's unusual for cave divers to dive doubles with metal knobs.

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This seems odd but i pay little attention to the new folks or what they are being taught. When I started cave diving basically all my instructors praised metal knobs for this exact reason, Maybe this is old school and no longer cool but my buddy and myself still use them. Being from Florida and diving Florida caves for the last 20+ years I felt my experience on the subject was relative but perhapse others are much more informed on this type of thing. Also, if it's that big of a concern then just dive independent singles mounted as double and mount one backwards

 

[Trace Malinowski]

Yes, metal knobs are more difficult to roll-off but they lack the shock absorption of rubber knobs. A metal knob is more likely to be bent, jam, and possibly not be able to be turned.

Everything in diving is a trade off.

Long hose left side means the rescuer is generally safer and the victim is more likely to die.

Long hose right side places the victim's safety first, but if a rescuer panics with a left post roll-off, both die.

Training and constant practice are the keys to a safe OOG situation regardless of which philosophy one chooses. Personally, I prefer and teach right side long hose, but just because someone chooses the left side does not make that diver an idiot. That diver might be making sure he comes home. You're just an option.

 

[RTBDiver]

Yes, metal knobs are more difficult to roll-off but they lack the shock absorption of rubber knobs. A metal knob is more likely to be bent, jam, and possibly not be able to be turned.

Everything in diving is a trade off.

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Certainly is a trade off but unless something sheared or bent enough to cause a serious air loss in a hard collision, there still would be no reason to turn it anyways during a dive, When scootering I use doubles with protecto plates, are they no longer used either? I better get back to a class and learn why all this stuff is no longer pushed Next thing you know, Someone will tell me that a couple clorox bottles and three feet of rope do not count as a BC

 

[PfcAJ]

Metal knobs dent and don't absorb shock. Thats bad news. Valve guards have entanglement potential, as well as block access to the valves. They're just not needed.

All the valve roll off issues are fixed by one, simple thing: Reach back and check after hitting the roof. You don't need to throw equipment at the issue...

 

[Cave Diver]

Certainly is a trade off but unless something sheared or bent enough to cause a serious air loss in a hard collision, there still would be no reason to turn it anyways during a dive, When scootering I use doubles with protecto plates, are they no longer used either? I better get back to a class and learn why all this stuff is no longer pushed Next thing you know, Someone will tell me that a couple clorox bottles and three feet of rope do not count as a BC

Yes, everything is a trade off. In my diving, I try to take the tradeoffs that offer the minimal amount of risk. As previously mentioned, metal knobs are more likely to be damaged from shock than rubber knobs. I'd rather take the chance rubber knobs roll off and then turn them back on, than have a knob that doesnt roll easily, but is damaged and won't turn when I need it.

Scenario: going through a tight, silty restriction, you bang a metal valve and it gets dented slightly. Silt gets into your secondary and it starts to free flow. You try to shut the valve down, but it's stuck from the previous impact.

Incident analysis shows us that it's usually not one thing that goes wrong that causes the problem. It's a chain of events left unchecked that does so. If I can remove one item from that chain, then I attempt to do so.

With everything, you have to weigh the pros and cons of each choice and decide on your own personal risk assessment.

 

[Trace Malinowski]

Certainly is a trade off but unless something sheared or bent enough to cause a serious air loss in a hard collision, there still would be no reason to turn it anyways during a dive, When scootering I use doubles with protecto plates, are they no longer used either? I better get back to a class and learn why all this stuff is no longer pushed Next thing you know, Someone will tell me that a couple clorox bottles and three feet of rope do not count as a BC

Nope ... no more protecto plates.

This is due in part to the fact that cave divers are becoming even more conservation-minded as science, education, and experience makes us rely upon training, practice, and skill rather than equipment to prevent problems.

Added to which, at a time when diving equipment started to become gimmicky, nerdy looking, and technical accidents and fatalities were on the rise, Jarrod Jablonski started the tech, cave and now recreational agency Global Underwater Explorers (GUE) and the Halcyon equipment company. Jarrod and George Irvine III went beyond the Hogarthian backmount configuration and created a system of diving called DIR ("Doing It Right") during their record-setting Wakulla Springs exploration and survey dives in which they used Gavin scooters. Minimal and streamlined gear, standardized equipment and gases, standardized procedures, and high quality skill training captured the attention of the diving public. They made diving look cool, stylish, and sophisticated again when most divers were looking like harlequins. Many of today's technical divers have learned to dive from GUE courses or from other agency tech instructors who strictly or mostly follow the philosophy.

Part of that philosophy includes rubber knobs, right side long hose, and excellent scooter control and personal trim, buoyancy and propulsion skills. Helmets and protecto plates as well as Chlorox jugs are so 1995. DIR is becoming slightly antiquated and so year 2005 by advances in sidemount and rebreather technology, but the philosophy will remain for many years as one of the best ways to dive backmount configurations. I believe the skill set that Andrew Georgitsis (now president of UTD) created for GUE as training director will replace the open water courses as we know them today in the future.

Most technical and cave divers use right side long hose and many of these are now venturing into sidemount and rebreather diving. Helmets are only for sidemount, no mount and the motion picture industry nowadays.

 

[Cave Diver]

Long hose left side means the rescuer is generally safer and the victim is more likely to die.

Long hose right side places the victim's safety first, but if a rescuer panics with a left post roll-off, both die.

That diver might be making sure he comes home. You're just an option.

Damn. Now I know why some people prefer solo! :shocked2:

 

[RTBDiver]

Nope ... no more protecto plates.

This is due in part to the fact that cave divers are becoming even more conservation-minded as science, education, and experience makes us rely upon training, practice, and skill rather than equipment to prevent problems.

Are they really? Are forgetting the minute thing about bouancy control? Why are so many concerned about rolling off a rubber knob valve? Personally, my valve protectors never got any use but i did put them on when i saw a buddies zepp get stuck on causing a crash.
Cant argue with all the names you drop, some good divers there and while asked years ago to participate in some of their dives i had to refuse due to my feeling that I am a recreation cave diver and believing in the part about never propmoting cave diving but offering instruction for those interested. Once involved with a manufacturer that stuff goes out the door. That along with the fact some of my instructors are now dead may suggest other options should be looked into, Afterall, What did Berman and Exely know anyway
PLEASE, Forget the name dropping crap

As far a bending/breaking metal valve knobs, Have you even see the tollerances? They are minimal even when fully opened. You might put a wobble in the valve but to cause anything significant would likely break the damn manifold, or are we also using the divers supply 200 bar setups that are converted for din?