All ships are required to keep a deck and engine room log in order to keep a record of activities during a voyage. The Deck log is kept by the officers of the watch and usually includes the following information:

1. Courses steered.
2. Compass errors.
3. Engine movements.
4. Daily distances covered.
5. Time of passing important headlands.
6. Positions and times of altering course.
7. Noon positions.
8. Weather and sea conditions.
9. Soundings of tanks.
10. In harbour:
    • The loading and discharging of cargo.
    • The draughts forward and aft.
    • The times of entering and leaving port.
11. Important details concerning emergencies and accidents.
12. Any other incident or happening of note.