Contingency Deco Plan

[PfcAJ]

so you're telling me that you carry 2x the maximum deco gas with two second stages on all of your deco bottles, or you plan to buddy breathe for multiple hours? That's not practical... we plan for very conservative deco with a gf high of 70, much lower than what you guys typically cut *which IIRC is around 85*.
If we lose a deco gas, while we will have enough in backgas reserves for backgas deco, we may very likely increase that GF high to 90 to get out quicker and just take it very easy at the surface and get to the reserve O2 bottles up there for 10-15 minutes before we haul gear out. Odds are extremely unlikely that you're going to have a valve failure, but it's possible and I'm not buddy breathing for any length of time

No dude you take 1.5x and share the deco gas. So a 2min stop becomes 3min and you each spend half the time on the gas. A 20min stop becomes 30min, etc.

The difference between gf70 and gf85 on most dives isn't a ton of time.

 

[PfcAJ]

No dude you take 1.5x and share the deco gas. So a 2min stop becomes 3min and you each spend half the time on the gas. A 20min stop becomes 30min, etc.

The difference between gf70 and gf85 on most dives isn't a ton of time.

I can't believe I'm even having to write about this.

Adjusting your deco conservatism as A solution to not carrying enough gas is one of the wackiest things I've seen in a good while. Thanks for the chuckle, scubaboard.

 

[_Ralph]

Some People/Training Organizations make this way harder than it actually is …. Aside from their convoluted planning based on ‘students’ (and then certified divers) not being able to follow a plan ….

If you loose significant back gas ….. GTF to your next gas switch (deco/surface) with your ‘buddy/team/partner/friendly leopard seal’


If you loose significant deco gas …. Share gas and extend your last stop.


Worst case in this scenario, is you get the neato experience of a chamber ride. The other alternative, you’re recovering a teammate ….

You should be carrying lots of gas for a dive. People seem to have a problem with the amount of gas some of us bring, and our numbers gas planning (ErMerGerd, yer SAC is herreblel! I breth nerthen, Erm Ersomest!). I’ve never been worried that I’ll run out of gas on a dive, let alone if Murphy showed up for some reason. If a teammate lost all their back gas, AND all deco gas on a dive. I’ve got them covered.

If I LOOSE ALL BACK GAS and DECO GAS, my team has me covered.

As some of us have eluded to (like PfcAJ) ... SIMPLE.




_R

 

[tbone1004]

I can't believe I'm even having to write about this.

Adjusting your deco conservatism as A solution to not carrying enough gas is one of the wackiest things I've seen in a good while. Thanks for the chuckle, scubaboard.

it's not as a solution to not carrying enough gas, it's a last resort contingency in the event of equipment failure. we carry enough to get out with backgas, and we carry 1.5x the planned gas. What that doesn't account for is the piling on of equipment failures or other events that can cause you to have to dip into those planned gas reserves, and knowing that we can go from gf70 to gf90 to cut a good chunk of deco out is not bad. Don't have the full version of multideco on this computer, so limited to 50% deco mix.
Changing 30/70 to 30/95 on a 2 hour planned bottom time with a 50% deco mix cuts out 30 minutes of deco. In certain scenarios that is helpful. If you're already at a GF high of 85 it's not worth it with a 10 minute savings, but with 30 minutes, it's nice to know that if you have to get out, you can

 

[PfcAJ]

it's not as a solution to not carrying enough gas, it's a last resort contingency in the event of equipment failure

Last resort isn't pushing buttons on a computer.

Last resort is your deco is done when you're out of gas.

 

[tbone1004]

last resort for me is up it to 95, and if you're cleared by then, you can make the choice to get out or not, but at least you know that they have cleared that gf high. Stay in as long as you want/can after that, but at least you know where the tissues are sitting

 

[PfcAJ]

it's not as a solution to not carrying enough gas, it's a last resort contingency in the event of equipment failure. we carry enough to get out with backgas, and we carry 1.5x the planned gas. What that doesn't account for is the piling on of equipment failures or other events that can cause you to have to dip into those planned gas reserves, and knowing that we can go from gf70 to gf90 to cut a good chunk of deco out is not bad. Don't have the full version of multideco on this computer, so limited to 50% deco mix.
Changing 30/70 to 30/95 on a 2 hour planned bottom time with a 50% deco mix cuts out 30 minutes of deco. In certain scenarios that is helpful. If you're already at a GF high of 85 it's not worth it with a 10 minute savings, but with 30 minutes, it's nice to know that if you have to get out, you can

Who on earth is doing a 2hr bottom time anywhere with 50% as the only gas???

Goodness gracious this thread is lulz!

 

[tbone1004]

the example was because I don't have unlocked multi deco on this computer, which I said. That said, the possibility is real if you have a valve failure on your O2 bottle and for whatever reason took a 50% bottle in.

Total runtime with backgas deco if you only have O2 and you have a valve failure. Which is a possibility if diving solo, or something happens to your buddy, or something happens and you have to dip into your gas reserves, etc. Odds are slim, not something you could plan for, but if **** has hit the fan that much, I can tell you right now I'm increasing my GF from 70 to 95 to get out of the water almost an hour earlier in that situation

Run time with 120min bottom time at 100ft on 32%
GF70-253
GF85-222
GF95-206

 

[PfcAJ]

Lol so now you've had a valve failure on your deco bottle after you've lost your buddy?

Valve failure and "for whatever reason took a 50% bottle in"??? Wut? You don't grab the wrong gas, you fix the broken piece of gear and do the dive when you have the right resources. Jeez Louise.

You guys are too much.

 

[tbone1004]

multiple reasons where you may want to take a 50% bottle to accelerate deco depending on the cave profile, and yeah, you could have a valve failure after you've lost your buddy. In that case you steal his gas, but you could also be diving solo and got stuck, or something else. You don't plan for it, but if it happens, I at least want to know I have options to get out with minimal risk of being bent