Sea Pearls 80 Aluminum Scuba Tank 3000 PSI

The Sea Pearls 80 is a single aluminum scuba cylinder that holds 80 cubic feet of air at 3000 PSI and comes fitted with a K-valve. It is the standard recreational cylinder, the format dive shops are set up to fill, and it is aimed at divers who are done renting and want a cylinder of their own.

Who this suits

Recreational divers on a single tank in warm or temperate water. If you already own a regulator and dive often enough to resent the rental counter, an aluminum 80 is the format you were going to end up with anyway.

It also suits anyone assembling a first set of gear. Nothing about an aluminum 80 will surprise a divemaster or a fill station, which is worth something on the day you turn up with your own tank.

Skip it if you dive cold water or a drysuit and get through gas quickly, where 80 cubic feet runs short and a larger steel cylinder makes more sense. Skip it too if you are moving toward technical diving, where DIN valves and manifolded twinsets are the point and a single K-valve aluminum tank is not.

80 cubic feet at 3000 PSI

Those are the two numbers that define the tank. 80 cubic feet is the free air it holds when filled to its 3000 PSI working pressure, and the two only go together: a shop that fills it short leaves you with proportionally less gas.

How long that lasts underwater is set by your depth and your breathing rate, not by the cylinder, so treat the figure as a yardstick rather than a promise. It is the yardstick, though: other recreational cylinder sizes get described as bigger or smaller than this one.

The K-valve and its 3/4-14 NPSM thread

The valve is a K-valve: one outlet, one on and off knob, no reserve lever. It is what almost every recreational first stage is built to meet, so your regulator connects without hunting for adapters.

The valve seats on a 3/4-14 NPSM thread, the standard connection for this valve type. That only matters on the day a shop services the tank, and then it matters a lot: the thread decides which replacement valve fits, and this is the standard one for the valve type.

Aluminum, and what it does to your weighting

The cylinder is aluminum rather than steel. An aluminum tank gets lighter in the water as you breathe it down, so you finish a dive more buoyant than you started it.

In practice you carry a little more lead than you would with a steel cylinder, and you feel the difference at the safety stop with a nearly empty tank rather than on the descent. Sort your weighting out on the first dive instead of guessing at it.

What you get back is availability. Aluminum is the format fill stations, rental racks and travel operators are set up for, and it does not ask for the outside-corrosion care a steel cylinder does.

The condition it arrives in

The cylinder is listed with a current VIP sticker and a current hydrostatic test. The visual inspection is the internal check a shop performs on a schedule; the hydrostatic test is the periodic pressure test that confirms the cylinder still holds its rating.

A fill station will turn away a tank that is out of date on either one, so a cylinder that is current on both can go straight for a fill. Both stay your responsibility once you own it.

The bottom line

This is the default recreational cylinder, bought for the reason people buy it: 80 cubic feet, 3000 PSI, a K-valve and the standard NPSM thread. It is not a cold-water tank, not a technical tank, and not a way to extend your bottom time.

If you want a tank that behaves exactly like the one you have been renting, and you want to stop renting it, this is that tank.

Specifications