Watchstanding, or watchkeeping, in nautical terms concerns the division of qualified personnel to operate a ship continuously. On a typical sea-faring vessel, be it naval or merchant, personnel keep watch on the bridge and over the running machinery. The generic bridge watchstanders are a lookout and an officer or mate who is responsible for the safe navigation of the ship. Safe navigation means keeping the vessel on course and away from dangers as well as collision avoidance from other shipping. An engineering specialist ensures that running machinery continues to operate within tolerances and depending on the vessel, this can also be accomplished from the bridge. A secondary function of watchkeeping is to respond to emergencies, be it on own ship or involving other ships.