Colored light fittings designed to use filament bulbs are not suitable for LEDs, claim the Cruising Association’s Regulation and Technical Services team (RATS), and therefore in the event of an incident could invalidate insurance.

Published 9 years ago, updated 5 years ago

LED Bulbs should not be used in navigation lights designed for filament bulbs

Replacing filament bulbs with white LEDs in tricolour navigational lights could result in vessels not being insured.

Coloured light fittings designed to use filament bulbs are not suitable for LEDs, claim the Cruising Association’s Regulation and Technical Services team (RATS), and therefore in the event of an incident could invalidate insurance.

White LEDs do not emit the wavelengths required to correctly illuminate the red and green sectors, and, as a result, the colours observed are totally outside of the IMO specifications.

In addition, a tungsten filament bulb has a single vertical wire as the light source, whereas LEDs emit light path angles greater than the permitted 2-degree cut-off limit between tricolour sectors. A boat’s heading will, therefore, be unclear to another vessel over a significant arc, and, the merging beams will give strange colours as they overlap.

This issue does not affect navigation light fittings designed to take LED bulbs. The MCA has issued a Guidance Note highlighting these problems, and a warning not to use LED white replacement bulbs in equipment designed for filament bulb use.