Hand pump for mini scuba tanks: refill a half-liter tank with no power

A bicycle pump works at a few bar. A mini scuba tank needs 200, about 2,900 psi. The OXSEA hand pump gets there by compressing the air in four high-pressure stages, one after the other. It has a built-in filter, a gauge to follow the fill and a high-pressure hose that connects to the tank. No battery, no outlet, no fuel.

How a fill goes

You set the pump on a flat, stable surface, connect the hose to the tank, put your feet on the base and pump. Steady, full strokes work better than fast short ones. The gauge climbs slowly at first, then the strokes get harder as the pressure rises. Stop at 200 bar.

Count on about 20 minutes for a 0.5 liter tank. It is real physical effort, closer to a workout than to inflating a tire. Two people taking turns make it easier.

Pump in fresh air, away from an engine, a generator or a grill. What goes into the tank is what you will breathe underwater.

What it fits

The hand pump fills the 0.5 liter tanks: the OX500 and the OX500Plus.

It does not fill the OX1000 or the OX2000. For those volumes, you need the 12 V / 220 V compressor.

When it is the right choice

• No power where you dive. A dock with no pedestal, a cabin on a lake, a beach, a small sailboat with a single battery you would rather keep for the engine.
• You dive a few times a season. One fill before you leave, one after a job. Twenty minutes of pumping now and then is no problem.
• As a backup. Kept on board next to the compressor, it still fills a half-liter tank on a day the battery is low.
• Budget. The hand pump packs are the most affordable packs in the OXSEA range.

When the compressor is better

• You use a 1 liter or 2.3 liter tank.
• You do several dives in a day, for example on a hull scrub that takes two or three fills.
• You would rather not spend 20 minutes pumping after each session.

The compressor fills a 0.5 liter tank in about 12 minutes on its own, from a 12 V battery or the mains.

Care

Keep the pump dry and out of the sun between uses, and rinse off salt spray with fresh water if it gets splashed. Check the hose and its fittings before each fill. If anything leaks or the pump stops building pressure, stop and contact the OXSEA team rather than forcing it.

Before the dive

A full tank is only half of it. Breathe continuously, never hold your breath on the way up, ascend slowly, and fly a dive flag: see dive flag rules in the US. The safety guide on oxsea.shop covers the rest.