A logbook (a ship's logs or simply log) is a record of important events in the management, operation, and navigation of a ship. It is essential to traditional navigation, and must be filled in at least daily. The term originally referred to a book for recording readings from the chip log that was used to estimate a ship's speed through the water. 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 A ship is a large watercraft, vessel that travels the world's oceans and other Waterway, navigable waterways, carrying cargo or passengers, or in support of specialized missions, such as defense, research and fishing. Ships are generally disti ...

submarine A submarine (often shortened to sub) is a watercraft capable of independent operation underwater. (It differs from a submersible, which has more limited underwater capability.) The term "submarine" is also sometimes used historically or infor ...

, such as weather conditions, times of routine events and significant incidents,

crew A crew is a body or a group of people who work at a common activity, generally in a structured or hierarchy, hierarchical organization. A location in which a crew works is called a crewyard or a workyard. The word has nautical resonances: the ta ...

complement or what

port A port is a maritime facility comprising one or more wharves or loading areas, where ships load and discharge cargo and passengers. Although usually situated on a sea coast or estuary, ports can also be found far inland, such as Hamburg, Manch ...

s were docked at and when. The term ''logbook'' has spread to a wide variety of other usages. Today, a virtual or electronic logbook is typically used for record-keeping for complex machines such as nuclear plants or particle accelerators. In military terms, a logbook is a series of official and legally binding documents. Each document (usually arranged by date) is marked with the time of an event or action of significance.

Shipping

Most national shipping authorities and admiralties specify that logbooks are kept to provide a record of events, and to help crews navigate should

radio Radio is the technology of communicating using radio waves. Radio waves are electromagnetic waves of frequency between 3 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmitter connec ...

radar Radar is a system that uses radio waves to determine the distance ('' ranging''), direction ( azimuth and elevation angles), and radial velocity of objects relative to the site. It is a radiodetermination method used to detect and track ...

or the GPS fail. Examination of the detail in a ship's log is often an important part of the investigative process for official maritime inquiries, in much the same way as a "

black box In science, computing, and engineering, a black box is a system which can be viewed in terms of its inputs and outputs (or transfer characteristics), without any knowledge of its internal workings. Its implementation is "opaque" (black). The te ...

" is used on

airplane An airplane (American English), or aeroplane (Commonwealth English), informally plane, is a fixed-wing aircraft that is propelled forward by thrust from a jet engine, Propeller (aircraft), propeller, or rocket engine. Airplanes come in a vari ...

s. Logbook entries are sometimes of great importance in legal cases involving maritime commercial disputes. Commercial ships and naval vessels often keep a "rough log", – or "scrap log" – a preliminary draft of the ship's course, speed, location, and other data, which is then transcribed as the "smooth log", – or "official log" – the final version of the ship's record. Changes may be made to the rough log but the smooth log is considered permanent and no erasures are permitted. Alterations or corrections in an official logbook must be initialled by the authorised keeper of the logbook and the original data entries which have been cancelled or corrected must remain legible.

In fiction

* The '' Hornblower'' series mentions logs to explain plot development, or to make the story more realistic. * In ''

Star Trek ''Star Trek'' is an American science fiction media franchise created by Gene Roddenberry, which began with the Star Trek: The Original Series, series of the same name and became a worldwide Popular culture, pop-culture Cultural influence of ...

'', the captain's log, a form of ship's log, is used to fill in the audience as to the events in progress, and acts as a

diegetic Diegesis (; , ) is a style of fiction storytelling in which a participating narrator offers an on-site, often interior, view of the scene to the reader, viewer, or listener by subjectively describing the actions and, in some cases, thoughts, o ...

form of

soliloquy A soliloquy (, from Latin 'alone' and 'to speak', ) is a speech in drama in which a character speaks their thoughts aloud, typically while alone on stage. It serves to reveal the character's inner feelings, motivations, or plans directly to ...

. This is part of a larger log system that includes personal logs (a sort of journal) and other officers' official logs, for stories that could not believably be reflected in the official Captain's log.

References

{{Authority control Navigation Maritime books Records management

Shipping

In fiction

See also

References