Cozumel dive ops with hp119s or hp120s?

[Mossman]

Here is one brand of high pressure steel tank showing a 3442 psi value

Buy XS Scuba 120 Cubic Foot [cf] hp steel tank X7-120 with reviews at scuba.com

I wish I remembered what tanks Jeremy uses. I'll check in April for sure.

Here's another popular brand, which might be the ones since these are 4lbs positive when empty just like an AL80 - I remember weighting more like I was diving an AL80 than what I would have normally expected to use for a steel 120.

Faber 120 Cubic Foot
Low Pressure Steel Scuba Tank
Eligible for Free
Standard Shipping on orders over $25

• Free Visual Inspection Program (VIP)
  Included!
• Includes
  Pro Valve-Standard Yoke and DIN Compatible
• 2640 PSI
• Nitrox Compatible to 40% (The Recreational Limits of Nitrox)
• Durable corrosion resistant finish
• Chromium Molybdenum Steel
• DIAMETER: 8.0 inches
• LENGTH: 29.3 inches
• WEIGHT EMPTY: 44.9 lbs
• BUOYANCY FULL: -4.87 lbs
• BUOYANCY EMPTY: 4.07 lbs
• FULL MANUFACTURER'S
  WARRANTY

~

 

[boulderjohn]

This should cover your possibilities.

Scuba Cylinder Specifications from Tech Diving Limited - 928-855-9400

 

[MMM]

Thanks everyone. He must have two different models I always have to add 4 lbs for my 2nd dive when I use nitrox. I will check when I am out next...probably in a day or two.

 

[kixy1]

Hmmm, this is interesting! Don't know why I never really thought about tank SIZE in relation to trim/comfort. I have issues with comfort after a few days, maybe the larger/longer tanks distribute the weight differently making it more comfortable? Women have a different center of gravity, and well, mine is ummm, considerably lower...

Dave brought up another thought for me too.. For a couple of years I've been fighting the "perfect weight" issue. If I wear what feels right at depth, I need to do the Pope blessing dance or just head down and kick to sink. It's not a huge fight, but I'm too slow of a sinker to keep up with everyone else. If I add the extra 2lbs I feel heavy at depth and need to futz with my bc. Safety stops are work for me unless I'm wearing that extra weight. I seem to be neutral at 20', not 15' so I either fight it or link up with my buddy. Maybe a larger tank would solve both issues?

 

[MMM]

Kixy, I don't have any clear cut answers for you. All I can recount is my experience. FWIW, I can hold a safety stop a lot better with a steel tank than an aluminum, even if I have breathed it down a lot which I try not to do. I don't wear ANY weight except for the tank (when diving air...see my earlier comment re the nitrox tanks and likely a different model). It DOES take me a while to descend and I usually have to kick to get down. Part of that is likely due to the many, many mm's of neoprene I wear. Once I get down a bit that all compresses. If I wore weight that made it easy to get down, I would most certainly be overweighted at depth (maybe you just need more time to get down and the tank is immaterial?). The dive op and I are familiar with all of this and so no one frets that I am usually the last to hit depth. The great thing about Cozumel diving is everyone being able to see all this going on. I suspect this could present different challenges when vis is low and current is strong. At the end of the day, maybe the only way to find out is to do a few days of diving with steel tanks? And then you will know one way or the other. Yes?

 

[kixy1]

At the end of the day, maybe the only way to find out is to do a few days of diving with steel tanks? And then you will know one way or the other. Yes?

You got that right!! I'm already hatching my plans... and this is serious, scientific research that must be completed with care. I think I'll need at least a week, no TWO weeks of diving with different tanks, don't you think?

 

[Dave Dillehay]

Dear kixy,

That is one of the joys of the HP tanks, when full they are 8 lbs heavier than Aluminum tanks and getting down is easy. That is why so many people like their buoyancy characteristics. Then when empty at the end of the dive they are still not positively buoyant so you don't go bobbing to the surface. Take 4 lbs off your weight belt and enjoy the ride.

Dave Dillehay
Aldora Divers

 

[MMM]

Dear kixy,

That is one of the joys of the HP tanks, when full they are 8 lbs heavier than Aluminum tanks and getting down is easy. That is why so many people like their buoyancy characteristics. Then when empty at the end of the dive they are still not positively buoyant so you don't go bobbing to the surface. Take 4 lbs off your weight belt and enjoy the ride.

Dave Dillehay
Aldora Divers

Do you mean HP tanks or steel tanks generally? I have also dived with Liquid Blue's HP steel tanks and found buoyancy characteristics materially similar to Living Underwater's LP steel tanks.

 

[Ron Lee]

I like to be slightly negative at the safety stop. That means about nine to 10 pounds negative at the start of the dive. Non-issue for me. Example: AL80 Buoyancy Full = -1.4lbs, Buoyancy Empty = 3.4lbs Steel HP 120 Buoyancy Full = -11lbs, Buoyancy Empty = -2lbs Just looking at the buoyancy empty the steel 120 is 5.4 pound mo negative...so you could take off that amount of weight from your weight belt. Since you normally do not go to empty, Dave's suggestion of removing four (4) pounds from your weight belt is right on (surprise).

 

[Dave Dillehay]

Dear MMM,

I don't know what tanks liquid blue is using now but at one time they were using the same tanks we use, HP Steel. As others have described-- they DO have significantly different buoyancy characteristics than aluminum tanks or the LP Steel Tanks.


Dave Dillehay
Aldora Divers