Distress signals are official emergency indicators used by vessels to show that they are in grave and imminent danger and urgently require assistance. These signals are recognized worldwide under COLREGS Annex IV, ensuring that seafarers, coastal stations, and rescue authorities understand the situation instantly—no matter the language or location.

Distress signals can be visual, sound-based, or radio-based, such as red star shells, flares, flames on deck, SOS, Mayday calls, smoke, gunfire at one-minute intervals, code flags, dye markers, radio alarms, or waving of arms. Each signal serves the same purpose: to alert others that the vessel or individuals are in a life-threatening emergency.

Knowing these signals is essential for all maritime personnel, as they play a critical role in saving lives and enabling fast rescue operations.