Left Post Primary

[JS1scuba]

Greetings,

On another web board Dive Matrix a poster put up the following question.

http://www.divematrix.com/showthread...t-Post-Primary



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Left Post Primary

It is my understanding that a well known cave instructor is teaching left post primary and that there is a trend in at least the cave community towards this line of thinking. I have been unable to confirm this as the cave community sees anyone asking questions with less than thousands of posts as a lurker and troll. what are everyones thoughts on this practice, pros,cons,etc.

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This poster indicates that he is about to take a cave course with this "well known cave instructor" the thread has taken a variety of twists along the way and he has yet to reveal who the instructor is.

I do know that left post was popular a long time ago and that over time it has shifted to right post primary in both cave and wreck communities. I know of at least one cave guy who insists on left post primary, and I know we have sold a fair amount of 90" hoses for that purpose over the years. Since the guy who wants the info is a bit gunshy about asking the questions over here I thought I would post the question. (since you all know i am never gun shy) (oh and it's not my question)

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So ... who out there is teaching left-post primary and why?


Thanks for your help

Cheers

JDS

[Jim Wyatt]

Gas sharing .. zero visibility in a small passageway.

Donor rolls off left post, OOA diver is SOL.

Left post roll offs DO occur in the overhead.

Long hose off the left post is a bad idea.

[SLIM]

Come on Joel you know beter then that.

Like you said it is an old way that as I know is no longer tought. I think that both IANTD and NSS-CDS no longer teaches it that way or even approves of it like what Jim said.

If the guy is to gunshy to say who his instructor is or even ask the question, I think he needs to move on or just get used to what he will go through as he starts posting on the diving boards.

SLIM

[Sludge]

Gee whiz, Jim, how many catastrophes are you running here? Buddy loses his gas, you have a zero-vis situation, then a roll-off?

I'd say these guys' number was up.

[Marc Bryan]

Gee whiz, Jim, how many catastrophes are you running here? Buddy loses his gas, you have a zero-vis situation, then a roll-off?

I'd say these guys' number was up.

How about the rolloff happens in tight quarters during an OOG, the receiver freaks out and trashes the vis. Now a simple issue has become a cluster.

Right post for me.

[JS1scuba]

Guys, i'm the volunteer messenger here ...... but i thought it would be an interesting cross post ......

anyone out there still doing this ?

cheers
jds

[OutlawCaver]

The roll-off may be less likely but zero viz is very probable since both divers are probably going to loose buoyancy control while getting the gas share going. Provided the line has not been lost they will have to decide which way to go once on it in reduced or zero vis. Been there and it happened so fast.

I know, I know ......Of course there are others on this forum who are perfect under all stress levels and will maintain perfect trim while isolating a roiling free flow coming off their manifold while maintaining visual contact with the line and their buddy and then flawlessly receiving a deployed long hose, establishing touch contact and lining up on the line and exiting.

[jj1987]

A roll off isn't that unreasonable.

I was diving a cave and was going through a restrictive passageway when I got the absolute worst cramp I've ever had underwater. I tried to swim it out, but it was getting worse. With 3800ft to fresh air, and 700-800ft to my scooter, it was going to be a long swim. I tried to stretch it, and that resulted in twisting around, bumping the ceiling, and having my left post roll nearly completely off.

[sea2summit]

I never thought about roll offs as a posibility until I went CC and I only open my valves a turn/turn and half now I have them all the time. It amazes me how I don't even notice contact and it shuts me down. I think it is a very real posibility especially in a OOA/paniced diver situation

[netmage]

No............