LED and pyrotechnic distress signals can both produce conspicuous light, but they work in very different ways. Understanding those differences helps boat owners choose a sensible combination of alerting and locating equipment.
A pyrotechnic flare creates intense light by burning a chemical composition. Depending on the type, it may be hand-held, launched as a parachute rocket or produce orange smoke. The signal is extremely conspicuous but normally lasts for a relatively short period and the flare is then spent.
An LED distress signal uses electrical power to drive light-emitting diodes. It does not burn a pyrotechnic composition, so it can be switched on and off, tested before departure and, if rechargeable, restored to full charge after use.
Pyrotechnic flares are internationally recognised distress signals when they meet the relevant requirements and are used in the forms listed in COLREG Annex IV. Their intense output is one reason they have been used at sea for generations.
Electronic signals take a different approach. They can provide a repeating visual pattern for a much longer period, which may be useful when rescuers are already searching for a casualty. Practical visibility depends on luminous intensity, colour, flash pattern, beam geometry, weather and the background against which the light is being viewed.
This is one of the clearest operational differences. A pyrotechnic flare cannot normally be activated to prove it works and then returned to the safety kit. Its condition is assessed from storage, inspection and expiry information.
An electronic device can be functionally checked. That does not remove the need to maintain batteries, charging equipment and seals, but it does let the user confirm that the unit operates before leaving harbour.
Pyrotechnics require careful storage because they contain energetic materials. They also have a finite service life and disposal can require an approved route. Electronic devices avoid the storage and disposal issues associated with spent or expired pyrotechnics, although batteries still need appropriate care and eventual recycling.
In the UK, the answer depends on the vessel and the equipment it is legally required to carry. The MCA currently states that EVDS should not be substituted where approved pyrotechnic flares are mandatory. EVDS can, however, be carried in addition to required equipment and can be useful as visual locating devices.
For the current UK position, see MCA Marine Information Note 542 Amendment 3 and the RYA EVDS guidance.
That is usually the wrong question. Distress safety works best as a system. A recognised alerting method such as VHF DSC or an EPIRB can raise the alarm and provide position information. Visual equipment then helps rescuers identify the casualty. Depending on the vessel, area of operation and regulations, pyrotechnic and electronic signals may have different roles in that system.
UltraFlare Daylight is designed as a rechargeable, high-output visual locating signal. Learn more about its optical system and independent testing.
Last reviewed: October 2026. Always check the current carriage requirements for your vessel.