Ammonite System redefines exploration lighting with the launch of the LED Nautilus MKII

For technical, cave, and wreck divers, a reliable Primary Light (corded) is the absolute cornerstone of underwater safety and exploration success. When Ammonite System introduced the first-generation LED Nautilus head, it quickly became an industry staple thanks to its adjustable beam angle and rugged build. The new LED Nautilus MKII represents a complete engineering overhaul: lighter, faster-cooling, and dramatically more efficient.

Optical breakthrough: less power, more penetrating light

The original Nautilus relied on a large Cree CXB COB chip. The MKII executes a massive technological shift by upgrading to a single high-efficiency LUMINUS SFT-70.2 LED paired with a refined focal-length Fresnel lens.

Unicase technology: structural cooling

Early first-generation Nautilus units utilized a separate radiator element screwed into the main chassis. Driving a 40 W LED inside a compact casing generated thermal stress that required firmware adjustments to manage internal temperatures.

The Nautilus MKII addresses thermal management with Unicase construction. The core housing surrounding the LED chip is CNC-machined from a single block of hard-anodized aircraft-grade aluminum. Sitting in direct contact with ambient water, the entire body operates as an instantaneous heatsink, keeping the head thermally stable and extending electronic lifespan. A temperature sensor supervises the LED continuously: as the temperature rises, output is reduced whenever necessary. This protects the LED from damage and remains practically unnoticeable to the diver.

Record-breaking burn times

By cutting energy consumption by 25% (40 W down to 30 W), the MKII unlocks up to triple the runtime on standard Ammonite System battery canisters (ACCU) without requiring larger power packs. Beyond the change in LED power, the light levels on the magnetic switch have been re-set so the light uses its energy more economically:

Both generations maintain real-time battery monitoring, flashing a low-battery strobe before dropping into the automatic 1-hour “Take Me Home” reserve mode for safe ascents.

Refined ergonomics and magnetic control

During multi-hour dives, ergonomics make a critical difference. The MKII features a streamlined profile, shedding weight from 415 g down to 366 g to reduce wrist fatigue on a Goodman handle.

The legacy Delrin polymer adjustment knobs are replaced by an intuitive magnetic clutch ring. The mechanism turns smoothly with tactile resistance, allowing effortless beam adjustments from 4.7° to 60° while wearing heavy drysuit gloves.