Rapid Offensive Units (ROUs) consist of little more than engines, weapons and the ship's Mind. While some ROUs are crewed, the crew complement on such vessels is much smaller than those of the more general purpose ships of the Culture, such as General Contact Units and General Systems Vehicles. ROUs and their demilitarised versions, Very Fast Pickets, are the Culture's fastest ships and have so far been described as having been outrun only once, by a GSV that self-optimised for speed (in the novel Excession). Immediately after the Idiran War, ROUs of the period could also be outrun by the small number (described as a limited edition by the Drone Skaffen-Amtiskaw) of Continent Class, subtype Prompt GSV. Subsequent developments have of course rendered this state of affairs obsolete, though the events involving the Excession give the lie to this assumption.
Known classes are:
Killer Class (200 meters long)10
Inquisitor Class (prototype)