dive planning @ 300' cont.from D&T

[The Chad]

We call that a travel gas where I'm from

 

[wedivebc]

Loosing both 32 and 80 would not be that far fetched?

I actually had a situation using those very mixes coincidentally where my buddy open up his 80% and had a bad free flow. He was preparing to go to his lost gas plan when I signaled to him to go to backgas, we pulled the reg off his 32% put it on his 80% and went back to primary deco schedule treating the perid during the switch as an air break.
Pretty hard to imagine a scenario with both deco gases lost.
FWIW I like 80% when I need a little more volume than I can get in an al80 at 2000psi which is what my supplier gives me O2 at. Sometimes logistics wins out over idealism when it come to "real" diving.

 

[Cave Diver]

stage = an al80 of backgas mix breathed first before switching to backgas

We call that a travel gas where I'm from

Travel gas is used to get from surface to depth.

Backgas is used at depth.

 

[cfenton]

FWIW I like 80% when I need a little more volume than I can get in an al80 at 2000psi which is what my supplier gives me O2 at. Sometimes logistics wins out over idealism when it come to "real" diving.

Dave you need to get a booster

 

[wedivebc]

Dave you need to get a booster

Yeah, yeah, I know. My baby booster does not do big tanks very well.

 

[MauiScubaSteve]

What's with all this planning / discussion; some guys just grab an 80 and go for it!

http://www.scubaboard.com/forums/hawaii-ohana/229983-300-ft-dive-who.html

 

[Gombessa]

What's with all this planning / discussion; some guys just grab an 80 and go for it!

http://www.scubaboard.com/forums/hawaii-ohana/229983-300-ft-dive-who.html

Sounds like someone's chasing the wah wah.

 

[rjack321]

FWIW I like 80% when I need a little more volume than I can get in an al80 at 2000psi which is what my supplier gives me O2 at. Sometimes logistics wins out over idealism when it come to "real" diving.

~50cf of O2 is helluva alot in cold water. Then again I am doing alot more deco deeper too, so if I need 50cf of O2 I'm probably not doing the dive from a thermal risk perspective among other reasons.

 

[AzAtty]

I will say that the cont. plan with lost gas senarios is un-nerving.

That is a brilliant understatement. Gets my vote for best of the day.

 

[Web Monkey]

V-Planner 3.84 by R. Hemingway, VPM code by Erik C. Baker.
Decompression model: VPM - B

It works in vPlanner as long as nothing bad happens.

If you lose the tank of 32, the dive requires about 70 more CuFt of trimix than you have. (this is assuming a SAC of .75). I know the OP said .4, but that's just off in fantasy land for me in a drysuit and 4 tanks.

This would be one of those dives where I'd choose a nice burger and a beer over a close brush with death.

Terry