Aqua Lung Legend

At a glance

The Legend runs a balanced diaphragm first stage with automatic temperature compensation, environmentally sealed and certified for cold water below 10°C, in a marine-grade brass body with satin nickel plating. At about 910 g it is lighter than most cold-water-rated first stages here. The Legend LX second stage adds a pneumatically balanced valve with adjustable venturi and inhalation control.

What the regulator actually gives you

Where it wins and where it costs you

Full review: Aqua Lung Legend

Aqua Lung's Legend is built around two named systems that solve real problems. The Automatic Closure Device seals the first stage inlet when the regulator comes off the cylinder, keeping water out of the mechanism between dives, and the Adjustable Diaphragm System holds inhalation effort steady regardless of depth or tank pressure. Because the diaphragm design is over-balanced, breathing performance improves as you descend rather than degrading — the opposite of what an unbalanced regulator does on a deep dive.

The heat-exchanger design is what makes the cold-water certification meaningful. Extended external fins draw ambient water temperature into the incoming air, warming it enough to slow the icing that causes free-flow in near-freezing conditions. The Legend LX second stage pairs a large purge button and a Comfo-Bite mouthpiece with an adjustable venturi lever, so you can suppress free-flow at the surface and open the regulator up when you need maximum flow. An over-moulded exhaust tee keeps breathing resistance down on the exhale.

Construction is marine-grade brass with satin nickel plating and reinforced technopolymer where weight matters, and at roughly 910 g the first stage is unusually light for something certified below 10°C. The maintenance interval is longer than most balanced diaphragm designs, though annual servicing still applies and Aqua Lung wants that done by a certified technician for full warranty support. The main practical limitation is hose routing: without adapters, port options are narrower than on the Apeks alternatives, which matters if you are building a technical rig rather than a recreational one.