Selecting a tank

[Coll]

I'm sorry if this has been beaten into the ground but I just wanted some individually specific suggestions. I'm looking into purchasing my first tank, I am a recreational diver, not diving usually to more than 100' using a single tank set-up. I dive in Monterey but will be moving to San Diego so I'll still be diving in mostly cold water so I would like a steel tank. I've only dove aluminum tanks that I've rented so I don't know much about selecting a tank. If you guys could offer suggestions as to brands or any of the other multitude of things to take into consideration I would truly appreciate it. I don't need a huge tank, just something good for cold water recreation. I'm not opposed to purchasing a used tank either. Thanks very much for your help all! Here's to more happy diving!

 

[Scared Silly]

HP100 are probably the most popular in a steel HP cylinder. Similar size to an AL80 but with better buoyancy characteristics.

 

[micklock]

I would go with a Worthington hp100 or hp80.

 

[spectrum]

If you frequently tease 100' then something closer to 100 CF is probably a good idea.

For cold water seeking steel is the way to go.

What remains is HP or LP.

HP is more compact (nice for less than tall people) lighter, more money and a little fussier to get perfect fills into.

LP is longer (trims better on tall divers) heavier, less money and easier to fill.

When I say weight I mean carrying weight, not buoyancy. Buoyancy will vary between brands and models. You want to be looking that the EMPTY BUOYANCY spec to compare against the +4.4 of most AL80s. This difference will tell how much lead you drop.

The HP100 is a really nice blend of size, capacity, weight and buoyancy.

A hot dipped galvanized cylinder is top drawer but most alternatives will still do well enough.

Pete

 

[ucfdiver]

Remember, if you want a HP130, but are worried about not being able to get a full fill (let's say the dive boat can only go to 3000psi), you still get more air than if you have a LP104 at rated pressure. These days, HP tanks are cheap enough that i don't see a reason to not get them, just know that not all dive shops can fill them to working pressure, so I'd get a size up from what you really need.

If you need to calculate tank volume at a certain psi, here's the formula:
volume/workingpressure*fillpressure=total cu ft

This can be used to calculate overfills on LP tanks, or underfills on HP tanks. There's a slight margin of error that increases as you get into the higher PSI range, but for 3600psi and less, my understanding is that this method is pretty accurate.

I get most of my fills in cave country, so LP/HP really made no difference, it was all about tank size. If you're in an area like that, by all means save your money and get LP. If you ever travel, or your local dive shop won't overfill, I'd get HP.