Which steel tank to get

[ShakaZulu]

If you intend to double them up in the future, you may want to get some 100's?

 

[D_O_H]

well, I hope I didn't make a mistake today. My LDS let me put a couple of
PST E8 130's on lay away today. After my discount, then figure in the cost of a visual, tank of air and shipping, the online cost was about the same as the shop's. So for a couple of dollars more I decided that the LDS was worth it. But now I see the Worthington special and it has me thinking.

I love my PSTs and am not at all convinced that they're going to be worthless in the next few years (as some here are), BUT I would not pay much more for them than what's now being charged for the Worthingtons. If you did, you might want to try to wiggle out of the deal. If you got a comparable price, enjoy your E-8 water coolers.

 

[spectrum]

You're on the right track with the steel cylinders.

I have 6 PST HP cylinders, 4 E7-80s and 2 of the prior genration 3500 PSI "100"s and like them. The viability of PST of a company as shaky but I'm not loosing any sleep about the long term usability of my cylinders. There are a number of threads that cover this adnauseum

The Worthington (XS SCUBA or SeaPearles branded cylinders ) are comparable with only slight differences in specifications. Given the current pricing, free freight etc. deals posted above these are very attractive, and available.

Here is a post I made that evaluates the AL vs HP steel cylinders. You can run the math with the 100 CF cylinder to understand your change.
http://www.scubaboard.com/showpost.php?p=1191538&postcount=16

Give your cylinder size careful consoderation. An overly large cylinder will make you work harder and burn air for the sake of lugging it. If you dive mainly with an AL80 single cylinder crowd a HP 100 should put you in good shape until your air usage comes down, then you'll be sitting pretty and have room to extend your dives.

Pete

 

[Web Monkey]

You've got to stop doing this:

I read ScubaBoard at work during long, boring database queries, and it's really distracting

Terry

If you intend to double them up in the future, you may want to get some 100's?

 

[cummings66]

Give your cylinder size careful consoderation. An overly large cylinder will make you work harder and burn air for the sake of lugging it. If you dive mainly with an AL80 single cylinder crowd a HP 100 should put you in good shape until

I need some clarification. How can a large cylinder make you work harder by lugging it around? Aren't you neutral in the water and therefore not carrying the tank? I can see you getting winded getting to the water on the other hand.

 

[H2Andy]

I need some clarification. How can a large cylinder make you work harder by lugging it around?

you have to work harder to move it underwater. it may not seem like much,
but it does make a difference. yes, you are neutral, but the tank still
has mass, and you have to spend energy to move that mass. you're not
weightless.

with doubles, it's very noticeable

 

[brianstclair]

I need some clarification. How can a large cylinder make you work harder by lugging it around? Aren't you neutral in the water and therefore not carrying the tank? I can see you getting winded getting to the water on the other hand.

It's a drag thing, too. The aerodynamic kind. More air in your BC to float more weight, plus a bigger tank (or doubles) all equals a bigger "hole" that you have to plow through the water which equals more work.

Brian

 

[Crawl79]

Don't you mean hydrodynamic?
Sorry that one was too easy.

 

[spectrum]

I need some clarification. How can a large cylinder make you work harder by lugging it around? Aren't you neutral in the water and therefore not carrying the tank? I can see you getting winded getting to the water on the other hand.

Lets not forget our friend Newton.
http://csep10.phys.utk.edu/astr161/lect/history/newton3laws.html

While cylinder and overall diver bouyancy is key to being vertically neutral in the water column you are still starting and stopping your entire weight. This applies to going forward as well as to navigating and moving arouns in general. Larger diameter cylinders like E8s or doubles punch a bigger hole in the water which also requires more work. Work means burning energy and that takes more air. The weight of the addition air is relevant when getting in the water and for the first part of the dive. My 100 CF weighs 1.6 LB more than my 80 just in air mass. The difference in cylinder weight can be considrable and the cylinders empty buoyancy can go either way depending what you are comparing too. My 100s are 6.1 pounds heavier than my 80s and requie 1 pond more of lead since they are not as negatively buoyant.

Specifically I'm referencing E7-80s and PST 3500 PSI HP 100s

All told I am almost 10 pounds heavier starting a dive with the 100 CF tank. The air volume is nice when I need it, or for 2 modest dives. the longer cylinder trims out better in my drysuit but when spring comes and I'm diving wet again the little light E7-80 will be my cylinder of choice for basic shore dives.

For many divers getting too and from the water is also a significant, especially at the end of the dive and for smaller divers. The weight of the gear is no small reason why many divers say the heck with diving and that's why I consider it an important criteria.

Pete

 

[strazz]

If I had some extra cash, I'd jump on DRE's sale. Lloyd's prices on PSTs and Worthingtons aren't bad, but DRE's are MUCH cheaper right now, e.g. Lloyd has 130s for about $430, but DRE's are on sale for $289. I haven't seen a decent selection of steel tanks at any of the other local stores. Another nice thing is that even UPS will get a package from Pompano to Gainesville overnight DRE is a great company and I order from them often.