Rapid short blasts of the ship's whistle for a period of not less than 5 seconds, supplemented by the same signal on the general alarm bell.

Rapid short blasts of the ships whistle for a period of not less than 10 seconds, supplemented by a continuous ringing of the general alarm bell.

A long continuous blast of the ships whistle for a period of not less than 10 seconds, supplemented by the continuous ringing of the general alarm bell for not less than 10 seconds.

A long continuous blast of the ships whistle for a period of not less than 5 seconds, supplemented by the same signal on the general alarm bell.