Mast
A Mast is a tall vertical (or near-vertical) spar rising from the deck of a vessel. On sailing ships the masts carry the sails and rigging; on modern powered ships they carry navigation lights, signal flags, radar, antennas and communication equipment, and provide a high point for lookout and signalling.
Sailing vessels are often classified by the number and arrangement of their masts — a single mast (sloop, cutter), two masts (ketch, yawl, schooner, brig), or three or more — which, with the rig, defines the vessel type. Masts are supported by standing rigging (shrouds and stays). On merchant ships the foremast and mainmast, and structures like the radar mast, carry the essential navigation and signalling gear required by the COLREGs (lights and shapes). The mast is a fundamental part of a ship's structure and identity, central both to traditional sail and to modern navigation and communications. It remains a defining feature of a vessel's profile.
The mast defines a sailing vessel's type (how many, and how arranged) and, on modern ships, carries the lights, shapes, radar and antennas that navigation and the COLREGs depend on. From sail to satellite, it has always been the ship's high point — a fundamental part of any vessel's structure and identity.
What do masts carry on a modern ship?
Navigation lights and shapes, signal flags, radar, antennas and communication equipment, plus a lookout/signalling point.
How do masts classify sailing vessels?
By their number and arrangement — one mast (sloop), two (ketch, yawl, schooner) or more — which with the rig defines the vessel type.