Thoughts on post roll-offs and first stage hose routing

[Tortuga68]

Silt is fun

Wrecks tend to collapse over time - caves can (rarely) do it rather suddenly

Freshwater caves are cold!

Anyway... all good

The only cave where I regularly dive is Mapating (Tagalog for Many Sharks) Cave off Puerto Galera... lots of marble rays, and sharks of course

45-60m though :buggy:

 

[ianr33]

'Conventional' doubles hose routing is long-hose primary on the right post and secondary on the left post

In an accidental overhead roll-off (closing of the valve), the left post is more susceptible to roll offs given that the diver is most often moving forward

Potentially you could donate your primary to an OOG diver/as part of an S-drill, switching to your secondary and *oops* no gas

While it shouldn't be a big deal to reach back and turn the valve back on, it's not an ideal situation

There is another reason for the standard routing no one has mentioned so far:

OOG diver in front. Diver in rear rolls off left post in tight restriction causing loss of breathing gas on secondary. Normally he would just turn the valve back on,but in the event of the restriction being too tight to reach the valve it's theoretically possible to breathe off the wing inflator (which comes off the right post)

If I would have the presence of mind to actually do that is another question!

 

[CamG]

Great conversation guys and I have heard that mentioned before in a emergency ianr33 though I have trained only once for that in OW.
Good dialogue with lots of clarification of proper technique that is awesome!
One of the reasons I love this forum is the quality of the conversation!

Tortuga68 you are going to love cave training my friend!
It has been the best training and challenging as of yet!
It promotes an awareness that keeps you thinking ahead and planning for issues where hazards are present.
The line drills, communication, raise the skill level of any diver who really takes hold of the training.
Your diving will be changed as you incorporate these skills into all of your pursuits.

Cave Diver I commend you for your posts and thank you for all that you do!
Many appreciate the manor in which you conduct your duties here on SB!
Top shelf my friend!

Safe diving everyone!
CamG Keep Diving....Keep Training....Keep Learning!

 

[Tegg]

I have a simple question that should be pretty obvious to answer for those watching this thread...

"The Wart".... Exactly how many certified cave dives do you have? (dives in a cave after cave training)?

Thanks.

 

[Tortuga68]

There's been a free exchange of ideas, points have been well made and accepted, it's been a useful and informative discussion which you weren't a part of. There isn't any need to make it personal, especially at this late stage... or any point served by doing so. Thanks

 

[Tegg]

There's been a free exchange of ideas, points have been well made and accepted, it's been a useful and informative discussion which you weren't a part of. There isn't any need to make it personal, especially at this late stage... or any point served by doing so. Thanks

Actually, due to his responses and "comments" like...:

This would mean that your buoyancy is shocking that there is so much contact with a cave roof; therefore you should not even be cave diving.
I keep my long hose left. The reason? if it does roll off I'm the first person to know about it.
--------
We're assuming that a cave-diver who is capable of dealing with some seriously tight restrictions has actually been negligent enough to forget to check is SPG.
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If a cave was so retrictive (sp?) and the leader was the OOG then surely it would be impossible for him to take the lead.

He is making posts that he tries to assert in some manner that he knows anything about cave diving and OOA situations and protocols. Yet by his posts, it is obvious that he has not had training nor has he had any cave experiece. As such comments like the above, especially "This would mean that your buoyancy is shocking that there is so much contact with a cave roof; therefore you should not even be cave diving." should not come from his keyboard.

I have no problems with the discussions that took place, but several pieces as to why the OOA diver leads on the exit and which post the long hose should run from have been explained by cave divers who may/may not have been in these situations in a cave.

Cave tunnels are not all tubes. The protocols are there to make the exit as smooth as possible should there be an OOA diver. Things like putting the OOA diver up front as soon as feasible, choosing the proper post for hose routing, and pace of exit are all part of the training for a reason.

Again, the discussion on this topic has been good, but the nature of his replies in the thread warranted some disclosure on his part about his own experiences.

 

[Tortuga68]

I don't disagree but if as you say:

I have a simple question that should be pretty obvious to answer for those watching this thread...

...then the question is redundant and not contributing to the thread topic/s in any way

 

[RTBDiver]

I admit, I have not read every post in the thread and only found it after THE wart posted some silly stuff elswhere. From what i have read it seems odd that valve roll off is even an issue as in most instances here we are talking environments without gloves and a simple brass knob eliminates that problem in all but maybe the most extreme roof rubbing I could imagine. As far a hose routing, Thats simple, Route how you are comfy with as long as it works, it should have nothing to do with roll off and all to do with effectiveness

 

[Cave Diver]

Route how you are comfy with as long as it works, it should have nothing to do with roll off and all to do with effectiveness

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.

 

[Trace Malinowski]

Post roll-off's aren't just a concern in overhead diving. Anchor lines can roll off posts as well. In my last triox class, I gleefully watched as one of my students ascended the anchor line in a strong current in sweet trim while his right post was being rolled off by the mooring line to the Spiegel Grove. He barely escaped a complete roll-off.

I was totally disappointed because I thought the environment was going to give him an education on line awareness. I did have him check his post knob on the boat and he was surprised how many turns it had rolled.

If there was one reason why open water divers should be able to do a valve drill this is it. I've seen this happen more than once. My friend Bob witnessed a complete roll-off in a similar situation.