Using bottom stages

[rjack321]

I know ALOT of Tech1 level people using bottom stages for one reason or another. Mostly as redundancy in ice diving, to switch mixes on a 2 dive day (e.g. 21/35 in backgas using a stage of 32% for dive2), or to get 2x tech1 dives off of a smaller set of doubles like hp100s.

I am just wondering at what point you felt comfortable doing this? Have you ever had an UW problem that this practice created or exacerbated? Did you take any sort of seminar in this practice, receive some sort of mentoring? Basically how and why did you incorporate bottom stages into your diving.

 

[nadwidny]

I don't feel like answering everything so I'll just hit the highlights:

Have you ever had an UW problem that this practice created or exacerbated?

Yes. We were doing a dive in the 170ish range diving stages (I don't remember why we were on stages) with a planned switch to backgas. I switched then my buddy went to do the switch. Boom. Out of air signal. My buddy was getting no gas from the backgas regs. Out of gas procedure went smoothly and I checked the valves. Long story short- backgas had gotten turned off at the surface due to some unplanned friggin' around and not turned on again. Had we not been on stages they would have noticed that their backgas was not on at the start of the dive and not at 170 feet.

Did you take any sort of seminar in this practice, receive some sort of mentoring? Basically how and why did you incorporate bottom stages into your diving.

Nothing formal. We started the practice after some conversations with AG and based our own experiences.

 

[rjack321]

Thanks

Personally, I starting using them for 2nd no deco 32% dives using backgas as rock bottom first. Gradually working in using them to get 2 tech dives off one set of doubles.

The only problem I have personally seen them cause was a primary reg freeflow (not detuned) while scootering on the bottom stage. That can let loose alot of gas fast and with all the action the bubbles in the armpit are not necessarily immediately noticed.

I just figured with Andrew's new agency including a bottom stage at the Tech1 level (part2 actually) that it would be interesting to know what real world problems they have caused (esp by Tech1 who weren't formally trained).

 

[JeffG]

Thanks

Personally, I starting using them for 2nd no deco 32% dives using backgas as rock bottom first. Gradually working in using them to get 2 tech dives off one set of doubles.

The only problem I have personally seen them cause was a primary reg freeflow (not detuned) while scootering on the bottom stage. That can let loose alot of gas fast and with all the action the bubbles in the armpit are not necessarily immediately noticed.

I just figured with Andrew's new agency including a bottom stage at the Tech1 level (part2 actually) that it would be interesting to know what real world problems they have caused (esp by Tech1 who weren't formally trained).

I would use the stage first (before using BG) and I would have it turned off if I wasn't using it.

 

[rjack321]

I would use the stage first (before using BG) and I would have it turned off if I wasn't using it.

Sorry I wasn't clear...
My buddy was on the stage (breathing that 1st) and the right post was on. From the banging around in his armpit or maybe propwash his primary reg started freeflowing and he lost a bunch of gas (not an obscene amount but still disconcerting at 150ft).

 

[JeffG]

my bad.

 

[PfcAJ]

I don't feel like answering everything so I'll just hit the highlights:



Yes. We were doing a dive in the 170ish range diving stages (I don't remember why we were on stages) with a planned switch to backgas. I switched then my buddy went to do the switch. Boom. Out of air signal. My buddy was getting no gas from the backgas regs. Out of gas procedure went smoothly and I checked the valves. Long story short- backgas had gotten turned off at the surface due to some unplanned friggin' around and not turned on again. Had we not been on stages they would have noticed that their backgas was not on at the start of the dive and not at 170 feet.



Nothing formal. We started the practice after some conversations with AG and based our own experiences.

While the issue was handled, that should have been caught WAY before the switch.

This is a great thing to learn from on why we all need to check our valves at the start of the dive and when you reach the bottom.

 

[MonkSeal]

This is a great thing to learn from on why we all need to check our valves at the start of the dive and when you reach the bottom.

And from time to time make a flow-check

 

[jjones9527]

I started practicing with multiple stages in a quarry first with a few Tech 2 guys. After that we did some long scooter dives with multiple stages, but all bottom gas, and no deco. I was a bit of a mess on that first "real" dive, but nothing dangerous, just sloppy. After a few of those dives I'm comfortable doing the bottle rotations and gas switches, but am not ready to do it on a Tech dive yet. So far my focus and practice has revolved around multiple bottom gas stages, and not a stage switch, deco gas, and ascent. I'm sure with some practice I could get comfortable doing it, but I plan on doing Tech 2 this summer anyway.

 

[nadwidny]

While the issue was handled, that should have been caught WAY before the switch.

Yup

This is a great thing to learn from on why we all need to check our valves at the start of the dive and when you reach the bottom.

Yup

And from time to time make a flow-check

And yup.

But I suppose that's why we practice our drills, because things happen.