;On August 2, 1981, the ship Primrose grounded on the North Sentinel Island reef. Within a short time, shipmates on the immobile vessel noticed that men on the shore were carrying spears and arrows and building boats on the beach. The captain radioed for a drop of weapons so that the ship could defend itself, but did not receive them. Luckily, heavy seas kept the islanders away long enough for the crew to be rescued by helicopter.