learning american - bar to psi conversion?

[isurus]

I'm headed to the carribean shortly and I know american (and therefore i presume carribean) dive ops tend to use psi instead of bar. Can anyone just confirm the relevant conversion ratios and give any tips on anything specific to the us type diving ops I need to know?

 

[hdtran]

I'm headed to the carribean shortly and I know american (and therefore i presume carribean) dive ops tend to use psi instead of bar. Can anyone just confirm the relevant conversion ratios and give any tips on anything specific to the us type diving ops I need to know?

1 bar = 14.7 psi (approximately). You can use 1 bar = 15 psi.

Start your dive at 3000 psi; (e.g. 200 bar)

Signal "up" at 1000 psi (depending on your dive plan) (e.g. 70 bar)

Be at the surface with between 700 & 500 psi. (e.g. 50-30 bar)

Have fun!!!

 

[bradshsi]

Or if you want to be exact 1 bar = 14.503 psi

(Ok, I admit I'm an engineer and thus get excited about such minutiae)

1:15 is accurate enough for most things

 

[tedwhiteva]

One difference between the UK and the carribean -in the carribean a dry suit is what you change into after a dive.
eyebrow

 

[Charlie99]

The other difference you will see is that the tank sizes are for the amount of free gas, not the water capacity. You will probably be diving an AL80 --- about 77 cu ft or 2200 liters. Tank is about 11 liter size, 207 bar.

70 bar per per 1,000 psi is the most convenient conversion.
Full tank = 3000 psi = about 210 bar
Half tank = 1500 psi = about 100 bar
Normal ascent pressure is between 1000 psi / 70 bar and, 700 psi / 50 bar.

The other very useful metric/imperial conversion is that each 10' is 3m.

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On one trip to the Florida Keys I had a buddy from the UK that just absolutely, absolutely could not figure out the PSI/bar conversion. For the shallow Keys dives, what finally worked for him was "in the red, we should be on the boat, or at least at safety stop". In the yellow (1000psi on his rental gear IIRC), "we should be headed back".

It got me to thinking that maybe we ought to just have an SPG that looks like a car fuel/petrol gauge. Full, 1/2, 1/4/ 1/8 Empty!

 

[superstar]

I've got one of those color coded guages, green(suck all the air you want) yellow(time to find your buddy and plan your assent) and red(times up) It works great, a no-brainer, I don't need to know metric or imperial. No more mathematical equations for calculating conversions. It works great in the Carribean, Atlantic, and in Lake Michigan. I bet it works equally well in the UK.

 

[Walter]

Are you taking your equipment? If so there's no need to convert.

 

[WarmWaterDiver]

Be ready for non-DIN tank valves as well, in general.

Thanks for saying 'American' instead of 'Imperial' as well!

FWIW, Divers Supply used to sell Sea Elite pressure gauges with red, yellow, & green maked both in bar and psi. It appears these are being phased out.

http://www.diverssupplyusa.com/index.asp?PageAction=VIEWPROD&ProdID=16357

 

[freediver]

Whatever you do, just remember to never take a psi in a Caribbean bar. They tend to frown on that.

 

[Nomad]

Are you taking your equipment? If so there's no need to convert.

But if he fills his tanks in the Carribean, the air won't be metric. Therefore, he will need to use PSI to measure it...