The UK MCA has released a marine notice, MIN 542, which highlights the specific risks of using non SOLAS or non-pyrotechnic distress flares, for example Electronic Visual Distress Signals (EVDS).
To be effective, distress signals need to be internationally recognised. Not all EVDS provide a distress signal listed in COLREGS Annex IV (such as SOS), and the MCA knows of no EVDS device which is compliant with the SOLAS technical performance standards for distress flares. Consequently, the international carriage requirements do not recognise EVDS and the UK national carriage requirements have not been amended to formally recognise them either.