A continuous blast of the ship's whistle for a period of not less than 10 seconds, supplemented by a continuous sounding of the general alarm for a period of not less than 10 seconds, is the __________.
A continuous blast of the ship's whistle for a period of not less than 10 seconds, supplemented by a continuous sounding of the general alarm for a period of not less than 10 seconds, is the __________.