In its widest sense, is the whole art of taking a ship from one place to another at sea. It is an amalgam of all the arts of designing a ship and its motive power, whether sail, steam propulsion, or other means, of working it when at sea, and in harbour, and the science of navigation. It thus embraces every aspect of a ship's life in port and its progress at sea.
Seamanship, however, has also a narrower meaning. It is that area which is concerned with the rest of a ship's daily management and safe handling: its gear, boats, anchors and cables, rigging; its sails if it is a sailing vessel, and the organization of a watch kept at sea and in harbour. The old definition of a prime seaman was a man who could hand, reef, and steer—had, in fact, an intimate knowledge and understanding of the way of the sea and ships—and although the handing and reefing of sails in commercial vessels and warships is a thing of the past, the same general definition holds good if the modern equivalents are related to the powered ship of today, or to those who go yachting for pleasure. It embodies a knowledge of knots and how to splice, of handling ropes and hawsers, blocks and tackles; it embraces a knowledge of marine meteorology and of winds and tides, the means of riding out storms, the skill to apply the International Regulations for Preventing Collisions at Sea, and the necessary experience and judgement to interpret navigation lights and distances at night, in fact the day-to-day work of running a ship at sea in a shipshape and Bristol fashion.