bridges. As conning towers were eventually built large enough that crewmen could comfortably stand on top of them, the collapsible bridges gave way to fixed structures, leading to the development of the so-called "bridge fairwater". To clarify: The conning tower is the small watertight compartment above the control room, from which the boat's commanding officer would command the boat during submerged attacks. The bridge was built on top of—but not considered part of—the conning tower, and was used for surfaced navigation and signalling. The fairwater is a streamlined casing around the conning tower and/or around the bridge. The tapering aft end of this casing also provided a sheltered location for the boat's air intakes, as well as an elevated base for various AA gun platforms. In the post-1950s era, an increased focus on deep submerged operation together with improvements in technology that allowed periscopes to be made longer, removed the need for a raised conning station. (laid down 1956) was the last US submarine to have a conning tower, after which the conning tower's function as an attack center was integrated into the control rooms of subsequent designs. Thus it is incorrect to refer to the sail (fin in British usage), or fairwater of a modern submarine as a "conning tower". References External links Watercraft components Submarine design