advanced dive shop with small groups in Cozumel?

[krbailey]

I assume those tanks belong to BA? Like Christi's 100 nitrox?

I'm not sure.

 

[cvchief]

I'm not sure.

I bet they belong to them. You can fill whatever you want if you bring your own tank. You just can't get a 100CF properly filled. What was your starting pressure on the 100CF nitrox?

BA doesn't have a fill station do they?

 

[krbailey]

I bet they belong to them. You can fill whatever you want if you bring your own tank. You just can't get a 100CF properly filled. What was your starting pressure on the 100CF nitrox?

BA doesn't have a fill station do they?

BA had the tanks delivered each morning. To my knowledge, they don't have a fill station unless it is off-property. I had 3300 - 3500 psi in every tank.

 

[cvchief]

Really? Now that is interesting. Every 100cf air I have seen on the boat was at right about 3,000. The max fill is supposed to be 3,300. Maybe they just properly fill nitrox 100s? 3,500 is like a bonus.

 

[Ron Lee]

Really? Now that is interesting. Every 100cf air I have seen on the boat was at right about 3,000. The max fill is supposed to be 3,300. Maybe they just properly fill nitrox 100s? 3,500 is like a bonus.

3500 psi may have been a measurement after being heated by the sun.

PV=nRT

 

[cvchief]

3500 psi may have been a measurement after being heated by the sun.

PV=nRT

Good point. It would still take a pretty big change in heat to get it up from 3000 though.

 

[DjDiverDan]

3500 psi may have been a measurement after being heated by the sun.

PV=nRT

I'd be interested to know if you checked your pressure once you fully descended. On Second dives, after tanks have been sitting out for several hours, I often notice a drop of 250-300 psi by the time I get from the boat to the sandy bottom. I assume that most of that drop is just change in temp.

 

[Skittl1321]

I'd be interested to know if you checked your pressure once you fully descended. On Second dives, after tanks have been sitting out for several hours, I often notice a drop of 250-300 psi by the time I get from the boat to the sandy bottom. I assume that most of that drop is just change in temp.

Maybe you just have really bad air consumption

 

[DjDiverDan]

Maybe you just have really bad air consumption

NEVER -- it's just that the air on the top in that tank tasted bad, so I kept spitting it out until I got to the air I liked!

 

[gopbroek]

I'd be interested to know if you checked your pressure once you fully descended. On Second dives, after tanks have been sitting out for several hours, I often notice a drop of 250-300 psi by the time I get from the boat to the sandy bottom. I assume that most of that drop is just change in temp.

I also see a rapid roll-off in bottle pressure on afternoon dives when the bottles become heated by the sun. I recently went geek (or even more so) and purchased a download cable for my AI. I had known of the pressure verses temperature change in an abstract way but it was kind of interesting to see it visually on the graphed readout. Does anyone know of a chart showing pressure changes verse temperature for a standard AL 80? The pressure drop rolling off into Caribbean waters at 82-84ᵒF is noticeable, I am betting that in SoCal with their near artic water temp’s, it would be impressive.