Log buoy

A log buoy or recorder-marker is a device that is carried aboard starships, and should the starship face a situation in which destruction seems imminent, the buoy is launched and directed towards the nearest allied base. Log buoy's are built to withstand the completed destruction of a starship and many other external forces that could act upon it.

During the USS Enterprise's encounter with the Fesarius in 2266, Captain James T. Kirk had a log buoy launched with all the log entries when destruction seemed imminent. (TOS episode: "The Corbomite Maneuver").