ship’s bells

The ship’s bell is struck every half hour. A single stroke is struck a half hour after the beginning of each watch, at 12:30, 4:30, and 8:30 (both am and pm). An additional stroke is added at each tolling, every half hour, so that 8 bells is struck at the end of the watch. The interval between strikes is either one or two seconds, alternating. In the table below, the hyphen represents a 1-second interval and the long dash a 2-second interval.

Number of Strikes	When						How struck
1	12:30am	4:30am	8:30am	12:30pm	4:30pm	8:30pm	B
2	1:00 am	5:00am	9:00am	1:00pm	5:00pm	9:00pm	B-B
3	1:30am	5:30am	9:30am	1:30pm	5:30pm	9:30pm	B-B—B
4	2:00am	6:00am	10:00am	2:00pm	6:00pm	10:00pm	B-B—B-B
5	2:30am	6:30am	10:30am	2:30pm	6:30pm	10:30pm	B-B—B-B—B
6	3:00am	7:00am	11:00am	3:00pm	7:00pm	11:00pm	B-B—B-B—B-B
7	3:30am	7:30am	11:30am	3:30pm	7:30pm	11:30pm	B-B—B-B—B-B—B
8	4:00am	8:00am	noon	4:00pm	8:00pm	midnight	B-B—B-B—B-B—B-B

Ship’s bells are no longer rung on merchant ships, but the custom is maintained on passenger, training, and naval vessels.