What is a logbook?
A logbook was originally a book for recording readings from the a device called a chip log,
and was used to determine the distance a ship traveled within a certain
amount of time. The readings of the log would have been recorded in equal
times to give the distance traveled with respect to a given start
position.
Today's ship's log has grown to contain many other types of information, and is a record of operational data relating to a ship, such as weather conditions, times of routine events and significant incidents, ports that were visited and when. It is essential to traditional navigation, and still is used widely today for personal and commercial use.