Another Tables vs. Computers Thread

[Soggy]

You only get a signicant change in bingo air (rock-bottom as you call it) as you comnplete planned stops. The gain as a result of a single diver vs. two during the ascent just isn't that much, even coming up from 200 to a deep stop at 100, your buddy only contributes about 5 cubes to bingo.

I didn't understand a word of what you wrote.

 

[TheRedHead]

You guys must be airhogs or cutting the rock bottom very close. Ascending to 50 feet from 100 feet would add 500 psi to my gas supply (or subtract 500 psi from my rock bottom) and give me 15 minutes or more to finish the dive in a reasonable way. My rock bottom is more a min. gas volume at which I will remain at some depth.

 

[Thalassamania]

Sorry I was typing too fast and running out to dinner:

1) You only get a significant change in bingo air (rock-bottom as you call it) as you complete planned stops.

2) The gain resulting from supplying gas to a single diver vs. two divers during the ascent only amounts to about 5 cubic feet coming up from say 200 feet to a deep stop at 100 feet.

Thank you, clearer?

 

[Soggy]

2) The gain resulting from supplying gas to a single diver vs. two divers during the ascent only amounts to about 5 cubic feet coming up from say 200 feet to a deep stop at 100 feet.

I'm not sure where you came up with the term 'bingo air', or how you are calculating it, but to get from 200 ft to 100 ft sharing gas at a SAC rate of .75 per diver (*really liberal* for a gas share, I'd use 1 cft/min per diver) would take 3 minutes @ 30 ft/min at an average depth of 150 ft, 5.5 ATA. That's 3 x 5.5 x .75 x 2 = 25 cft of gas. That's a lot more than 5 cft.

 

[Thalassamania]

The term "Bingo Air" has been around for a least thirty years that I know of. I think it finds its origins in aircraft fuel consumption.

You're right I should never attempt to do math in my head when my wife is yelling that we've late for our dinner reservations. It did seem a bit low, but I really was not paying attention.

 

[Jason B]

You guys must be airhogs or cutting the rock bottom very close. Ascending to 50 feet from 100 feet would add 500 psi to my gas supply (or subtract 500 psi from my rock bottom) and give me 15 minutes or more to finish the dive in a reasonable way. My rock bottom is more a min. gas volume at which I will remain at some depth.

How are you calculating your rock bottom?

 

[Scubaguy62]

I think it finds its origins in aircraft fuel consumption.

That's true, and it's mostly used by military, or former military pilots; it refers to a pre-designated amount of fuel, for that trip, that would allow landing at the point of origin, and it is contingent on many factors, such as acft. weight, weather, distance, and a few others.

 

[Thalassamania]

So Bingo Air / Bingo Fuel are the same sort of concept? It is amazing how people seem to naturally think that they've invented the wheel just because it's come 'round again<G>.

 

[TheRedHead]

How are you calculating your rock bottom?

It's not really a rock bottom, which is defined at the minimum gas where you should start an ascent to the surface, but as a rule of thumb on multilevel dives. I use 100 psi per 10 feet plus 500 psi when I'm diving with an E7-100. It works drift diving and diving on sloping reefs where you work your way up the reef.

 

[Jason B]

So Bingo Air / Bingo Fuel are the same sort of concept? It is amazing how people seem to naturally think that they've invented the wheel just because it's come 'round again<G>.

I don't think anyone claimed to invent something new.