WHAT IS AN EVDS FOR?
Electronic boat flares, also called EVDS, use LEDs to create a recognisable distress signal that attracts attention and helps pinpoint position in low-light conditions.
WHAT’S THE DIFFERENCE BETWEEN AN EVDS AND AN EVDSD?
An EVDS (Electronic Visual Distress Signal) is a broad term for any LED distress light used for night-time signalling.
An eVDSD (electronic Visual Distress Signalling Device) is the regulatory classification for an EVDS that meets RTCM 13200.0. When carried with a USCG-approved day signal, it satisfies U.S. night-time distress carriage under 46 CFR 161.013 / 33 CFR 175.130.
Some people refer to EVDS by brand, such as “Eflare”, but only units tested and verified to RTCM 13200.0 qualify as true eVDSDs. In short, all eVDSDs are EVDS, but not all EVDS are eVDSDs.
WHY EFLARE EVDS?
The Halo Pro represents best-in-class compliance with the latest RTCM standard. By combining dual-colour SOS, infrared capability and precise flash sequencing, it eliminates ambiguity with ordinary lights. The focus is on recognition and endurance rather than competing with the short, intense illumination of pyrotechnics.
With six hours of activation, 50 candela illumination, and simple glove-friendly operation, the Halo Pro provides long-term mobile location marking. RTCM 13200.0 specifies a minimum operating life of two hours; Halo Pro exceeds this benchmark, offering extended visibility. Controls are designed for operation in total darkness and with neoprene gloves, ensuring usability in real-world rescue conditions. It complements the powerful initial alert of pyrotechnics and the positional accuracy of electronic beacons.
WHAT IS A COMPLIANT RTCM EVDS?
Early EVDS prototypes struggled because a white flashing light was easily confused with navigation lights. To solve this, RTCM developed Standard 13200.0, which specifies a dual-colour SOS sequence of red-orange and cyan at a minimum average effective intensity of 50 candela over the upper hemisphere, with no point below 25 candela. This ensures EVDS can be clearly distinguished from background lights, accelerating recognition by rescuers.
The visible SOS pattern uses red-orange and cyan lights, with a precisely defined “S” and “O” flash durations and spacing. Each device must also include a synchronised near-infrared SOS component for detection through night-vision equipment.
WHY RTCM DUAL COLOUR?
The alternating red-orange and cyan SOS pattern was established through U.S. Coast Guard R&D field testing and later adopted by RTCM 13200.0 as the most distinguishable and least confusable distress signal. This dual-colour sequence provides far greater recognition than single-colour white or red flashing lights and ensures rescuers can quickly identify a genuine distress signal at sea.
ARE EVDS ALTERNATIVES TO PYROTECHNICS?
No. EVDS provide long-lasting visual target illumination. They are designed to complement, not replace, pyrotechnics. Pyrotechnic rockets and handhelds create immediate attention; EVDS maintain a consistent target for rescue craft in low-light conditions.
RTCM 13200.0 prioritises clarity, pattern recognition, and endurance over extreme peak brightness, avoiding the temporary night blindness and rapid power loss associated with excessively intense light sources.
IS BRIGHTER BETTER?
Not necessarily. Excessive brightness approaching pyrotechnic levels can cause loss of night vision and shorten battery life. The Halo Pro instead uses advanced lensing to maximise clarity and recognition of the distress pattern, achieving full compliance without unnecessary intensity.
The standard defines distribution and patterning rather than raw output, ensuring the signal remains visible, identifiable, and safe for prolonged viewing.
CAN EVDS REPLACE PYROTECHNICS UNDER SOLAS REGULATIONS?
On Commercial / SOLAS vessels No. SOLAS Chapter III and the IMO LSA Code still mandate approved pyrotechnic signals, red hand flares, rocket parachute flares and buoyant smoke, carried under MED or USCG approval. These remain the only internationally recognised distress signals for regulated vessels because they deliver instant, high-intensity visibility in all conditions.
EVDS / eVDSDs are not approved for SOLAS carriage and cannot replace flares. Their role is complementary, extending visibility once the initial pyrotechnic or beacon alert has been made.
WHAT DOES “APPROVED NIGHT VISUAL DISTRESS SIGNAL” MEAN?
When tested to RTCM 13200.0 and carried with a USCG-approved day flag, a device is accepted by the U.S. Coast Guard as meeting the night-time visual distress carriage requirement. Together, the EVDS and flag combination fulfil the federal night-time signal obligation for U.S. recreational vessels.