Security Alert Teams are parties of crew members aboard United States Navy ships detailed to respond in the event of a security breach or threatened attack in port. A SAT is typically led by a Gunner's Mate under the authority of the Weapons officer, and is armed with the M9 or M1911A1 pistol, and 12-ga. shotguns (usually the Mossberg M500/590).
In most cases, a SAT is supported by a Backup Alert Force which is a team of crew members aboard US Navy ships detailed to provide overwatch and medium-range firepower in the event of a security breach or threatened attack in port, and to boarding and search parties at sea. A BAF is also typically led by a Gunner's Mate under the authority of the Weapons officer, and is armed with the M14 semi-automatic rifle in 7.62×51mm NATO caliber. The main purpose of these two teams is to cover the special weapons holds. They can only be told to stand down by the Captain, Executive Officer, Weapons officer, or the Duty officer if the first three are not present. That person must be escorted and have military ID for confirmation of the person to secure the detail. This detail can also be led by a Bosun's mate. Any unauthorized personnel who do not comply with the team's orders and continue to approach the secured area will cause the team to implement a security lockdown procedure. The approaching person will be placed on the ground at gunpoint until their security clearance is verified.