A distress light needs to do more than produce light. A recognisable pattern can help an observer distinguish an emergency signal from navigation lights, shore lighting and other flashing sources.
SOS is the internationally familiar Morse distress sequence: three short signals, three long signals and three short signals. It became widely recognised because the pattern is distinctive and can be transmitted by sound, radio or light.
A steady light may be mistaken for a vessel light or shore light, particularly in a harbour or near a populated coastline. A repeated flash pattern creates change, which helps attract attention when someone is scanning the scene.
Brightness determines whether a signal is visible at all, but recognition determines whether the observer understands that it is significant. A distinctive pattern can help separate a visual signal from background clutter.
A vessel rarely remains perfectly still. Pitch, roll and yaw move a directional beam across the observer’s field of view. A useful visual signal therefore needs a combination of appropriate intensity, beam coverage and a pattern that remains recognisable as the vessel moves.
UltraFlare Daylight uses a precision three-LED optical system with SOS and triple-flash signalling modes. The light pattern is only one part of the design. The optical geometry and peak intensity are equally important to practical conspicuity.
For more on these factors, read what candela means and why beam angle matters.