DESCRIZIONE
A rescue system 10 for rescuing a mariner at sea is described. The system 10 comprises a distress beacon 11 for the mariner, the distress beacon comprising a transmitter 111 arranged to transmit a first acoustic signal at a first frequency in water. The system 10 comprises a receiver 12 arranged to receive the transmitted first acoustic signal. The system 10 comprises a controller 13 arranged to cause an autonomous watercraft 14 for rescuing the mariner to be launched, in response to the received first acoustic signal. [Image Omitted]