Watchstanding regulate the sailors' duty watches and for other purposes (see main article). Unlike civil clock bells, the strikes of a ship's bell do not accord to the number of the hour. Instead, there are eight bells, one for each half-hour of a four-hour watch. Bells would be struck every half-hour, and in a pattern of pairs for easier counting, with any odd bells at the end of the sequence. Watchstanding Watchstanding, or watchkeeping, in nautical terms concerns the division of qualified personnel to operate a ship continuously. On a typical seafaring vessel, be it naval or merchant, personnel keep watch
End of Watch filming. Gyllenhaal and Peña undertook five months of intensive training under the guidance of FitzSimons to prepare for their roles—this included 12-hour ride-alongs with multiple Greater Los Angeles Area law enforcement agencies up to three times a week, as well as training in hand-to-hand combat, police tactics and weapons. On his first ride-along, Gyllenhaal witnessed a murder during a drug bust. Tactical training was also given to the other actors playing police officers, including David Harbour, America Ferrera, Cody Horn, and Frank Grillo. "End of Watch" was filmed on location in South Central Los Angeles, primarily in the area of