type of submarine carries different weapons and has different missions, for the purposes of understanding their actions on the surface, they operate identically.
While submarines can operate in shallow water, submerging in less than 100 fathoms( 600 feet) presents challenges, such as the difficulty in avoiding vessel traffic that may not be aware of the submarine’ s presence, or the possibility of bottom contact. As a result, when proceeding to sea on routine operations, a submarine will usually delay submerging until it reaches an area where the water depth is at least 100 fathoms.
Bridge Manning: When on the surface, submarines are usually conned from the bridge at the top of the“ sail”( also called the“ fin” or“ fairing” by the Royal Navy but no longer called the“ conning tower” as it was during World War II). The bridge will be manned by an Officer of the Deck and a lookout, and during some maneuvers the Captain will also be present on the bridge. The Officer of the Deck or the Captain gives orders from the bridge cockpit to the Helmsman below in the control room using a public address type of announcing system or a sound-powered telephone. In addition to the Helmsman, the control room will be manned by a radar operator and fire control watchstander who tracks other vessels, a Quartermaster who keeps track of the ship’ s position, and a Chief of the Watch who operates the ship’ s mechanical systems. A ship’ s officer will be assigned as the Contact Coordinator in charge of the Control Room to maintain a lookout using a periscope, and to assist the Officer of the Deck on the bridge in deciding on collision avoidance maneuvers.
During heavy weather, such as when waves break over the top of the sail, the bridge watch is sometimes moved below deck and the Officer of the Deck conns the ship from the Control Room, similar to when the submarine is submerged. When this occurs, however, the lookout’ s view is limited to what can be seen through the periscopes.
When Vessels Meet: A U. S. submarine, when operating on the surface in narrow channels or areas with limited depth, is treated as a“ vessel constrained by her draft.” This means it is severely restricted in its ability to deviate
from its course due to the available channel width and water depth as compared to its draft. It will display a black cylinder day shape and also may display three all-round red lights in a vertical line in addition to the lights required for a power-driven vessel. It also may display, as a distinctive means of identification, an intermittent flashing amber“ Sub ID beacon.”
A surfaced submarine can be tracked using commercial radar systems, even those not specifically designed for military applications. The submarine’ s hull, periscopes, and antennas will reflect radar signals, making it possible to detect the submarine. Visual identification, however, especially at a distance, can be challenging. Although surfaced submarines have unique structures like a sail, radar masts, and antennas unlike those typically found on surface ships that can help differentiate them from other vessels, because of its low freeboard, surfaced submarines are often mistakenly identified as small vessels like fishing trawlers when first visually sighted.
U. S. submarines, like other U. S. warships, are equipped with Automatic Identification System(“ AIS”), but are not required under U. S. law to use it. All U. S. Navy ships, however, are now instructed to activate AIS in designated areas, with the specific implementation subject to command discretion based on operational needs and security considerations.
U. S. submarines will use bridge-to-bridge communication and will comply with the Bridge-to-Bridge Radiotelephone Act. In sharing information about its course, speed, and
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