MOD markings and Stages

[rookers]

Funny, I was just thinking about this the other day, and was considering posting the question to the GUE email list.
I can't think of a situation where I would mishandle/misjudge a deep stage v/deco bottle, so I am content with the current 1.6ATA PPO2 MOD markings. I have a pair of the dreaded 120's sitting in the rack right now, one with 35/25 and one with 30/30. The afixed analysis stickers are pretty clear. I kind of like the idea of 100' END markings on Ean32, its just that I already use my 120' marked bottles for that when appropriate.

 

[KMD]

I have two bottles marked with an MOD of 100. My reasoning is that is the maximum depth that I want to use the gas due to 32% narcotic properties.

I debated for a bit on marking them at 120, but in the end the fact that I am not doing deco dives and thus not likely at to actually need a 120 deco bottle. In fact I bet all but a really really small amount of divers would ever need a 120 deco bottle. Thats a pretty monster dive no?


If ever I do need one, or am involved in a project that I am donating bottles to, its a simple matter to peal off the "0" and put a "2" in its place.


Kevin

 

[AndrewJD]

I mark my 80cuft stages using duct tape and a marker. This allows for the MOD markings to be changed very easily to what gas is actually put in the bottle. 100 for 32%, 150 for 25/25, and 190 for 21/35.

 

[rjack321]

If you get to the point of doing dives needing a 120ft deco bottle don't have 30/30 lying around too and getting into the tank collection. Those are way way different dives. Definately analyze the gas, since there isn't a standard mix per standard marking. Marking should allow for being within 100ft END IMO.
32%= 100
30/30=120
21/35=150
18/45=190
for my stable

I see no reason to bring a 25/25 stage, but if I did I'd probably mark it 130ft since I would not want to be on that mix at 150ft around here, too narced in the dark.

 

[rjack321]

Is anyone not (semi-permanently) marking bottom stages at all? Analyze, label tape with %age, date and initials, put the reg on, dive.

 

[nadwidny]

Is anyone not (semi-permanently) marking bottom stages at all? Analyze, label tape with %age, date and initials, put the reg on, dive.

Moi..

 

[rjack321]

Moi..

Do you ever dive with more than 1 bottom stage? If you do, how do you check your switches, by the absence of a MOD sticker or by the analysis tape? Or something else?

Are you ever worried about grabbing the wrong unmarked bottle out of your vehicle or boat? (i.e. if you had bottom stages of various mixes for various dives packed) they both might have been analyzed, but for whatever reason you were distracted and setup a reg on a bottle that was adjacent to the one you intended.

 

[nadwidny]

Do you ever dive with more than 1 bottom stage?

Haven't needed to yet.

If you do, how do you check your switches, by the absence of a MOD sticker or by the analysis tape? Or something else?

If I did dive with 2 bottom stages, then they would both be up top and the deco gasses would be clipped to the leash. That's how I would check my switch. Also my stages are 80s. My deco tanks are usually 40s.

Are you ever worried about grabbing the wrong unmarked bottle out of your vehicle or boat? (i.e. if you had bottom stages of various mixes for various dives packed)

No more than I worry about grabbing the wrong unmarked set of doubles.

they both might have been analyzed, but for whatever reason you were distracted and setup a reg on a bottle that was adjacent to the one you intended.

There is the analysis tape to go by and I also re-analyze everything before I put the reg on.

There are exceptions. If I use 80's and not 40's for deco gas I put an MOD on. If I was dropping stages like in a cave I would put an MOD on.

 

[rjack321]

Thanks. I generally leave the MODs on. But I know some people don't and I was just curious under what circumstances.

 

[MonkSeal]

If I did dive with 2 bottom stages, then they would both be up top and the deco gasses would be clipped to the leash. That's how I would check my switch. Also my stages are 80s. My deco tanks are usually 40s.

MOD marking is used exactly to prevent practice like this. Positionig tanks is something you should not rely on for switching purposes. Since this is "Practitioners Zone" this has to be pointed out as wrong practice. Unmarked stages are simply wrong. How can your team confirm correct switch (even surface switch to stage) if you use unmarked tank? DIR switching procedures are consistent and arguments like "80's for stages and 40's for deco", "top-leash", etc. should not be considered as valid ones.