The obligation to render assistance to persons in distress at sea is set in UNCLOS Art. 98: “Every State shall require the master of a ship flying its flag, in so far as he can do so without serious danger to the ship, the crew or the passengers:
a. to render assistance to any person found at sea in danger of being lost;
b. to proceed with all possible speed to the rescue of persons in distress, if informed of their need of assistance, in so far as
such action may reasonably be expected of him.
It is repeated in the SOLAS Convention, Chapter V, regulation 33-1: ”The master of a ship at sea which is in a position to be able to provide assistance on receiving information from any source that persons are in distress at sea, is bound to proceed with all speed to their assistance, if possible informing them or the search and rescue service that the ship is doing so. This obligation to provide assistance applies regardless of the nationality or status of such persons or the circumstances in which they are found”.
The IMO Resolution MSC.167(78) also outlines such an obligation to render assistance, resting upon all vessels : “All persons in distress at sea should be assisted without delay.” “Prompt assistance provided by ships at sea is an essential element of global SAR services; therefore it must remain a top priority for shipmasters, shipping companies and flag States”.