On the high seas if you ignore a distress signal you can be held accountable.

When it comes to rescuing life at sea, two international conventions provide guidance. The International Convention for Safety of Life at Sea (IMO 1974) states that “the master of a ship at sea, on receiving a signal from any source that a ship or aircraft or survival craft there of is in distress, is bound to proceed with all speed to the assistance of the persons in distress informing them if possible that he is doing so.”