4,000-5,200 lumens, 6-10 degree beam. Lithium reaches 7-8 hours at full power. LED eliminated the risk of HID bulb breakage. Always a primary canister light plus 2 independent backup lights.
The technical community debates whether to use canister or non-canister lights, when it is worth investing in high-performance lighting versus more affordable options, and compatibility between different brands (Gralmarine, Light 4 Me). In cave diving, the choice of helmet-mounted light for speleodiving adds another layer of specialization. Criteria such as burn time, power, and ease of repair are evaluated.
Modern primary lights exceed 4,000–5,200 lumens with beam angles between 6 and 10 degrees, designed to penetrate turbidity in passages. The main advantage of the canister system is burn time: current lithium models achieve 7–8 hours at full power, compared to 2–4 hours for compact portable lights. Unlike older HID lamps, LEDs eliminate the risk of bulb breakage and allow multiple intensity modes. For long explorations, cave divers carry a primary canister light and two independent backup lights.