A. The determining factors that distinguish boats from ships has evolved over time. The term 'ship' traditionally referred to a sailing vessel having three or more masts. In modern times, however, a ship is usually classified as a vessel of more than 500 tons of displacement.
A. Displacement tonnage is a way to measure a ship's capacity. The tonnage expresses the weight of the water displaced by a vessel as it sits on the surface.
Q. So, a definition of a boat
A. Small, open (often) nautical vessel propelled by sail, oar, pole, paddle or motor. Use of the term boat for larger vessels, although common, is somewhat improper, but the line between boats and ships is not always easy to draw.
Q. What are ships and what are boats
A. Countless varieties of ships and boats are in use today. No-one would mistake a rowing-boat for a ship, nor an oil tanker for a boat, but here are a few on the dividing line:
The Chinese junk, with high poop and overhanging bow, is large enough to be classified as a ship, though in comparison to an aircraft carrier it would be like comparing a chihuahua to a St Bernard, though they're both dogs.
Another oriental style, the sampan - a wide, flat-bottomed skiff, often having a mat-covered cabin with living quarters - a familiar sight in eastern rivers and coastal waters, is a boat.
The lateen-rigged dhow, in which Arab merchants of the Middle Ages plied their trade along all the shores of Asia and East Africa, is still a common site throughout the Red Sea and Indian Ocean - though now often engine-powered - and, like the junk, is a ship.
In the 5th century the Vikings began to make the epic sea journeys that, even today, remain mind-boggling feats of daring. Even though their vessels were known as 'long-ships', by modern standards they are definitely boats. Deckless or half-decked, with elevated bow and stern, these early boats took the Norsemen to all the coasts of Europe and across the Atlantic, and even partly across the land on river routes between the Baltic and the Black Sea. The rugged whale-boat of the 17th-19th centuries was developed from the Viking type of construction and came to be used for numerous purposes, including lifeboats, and is still in use today.
In the US Navy, the term boat refers to any vessel that is small enough to be hoisted aboard a ship.
Q. And submarines
A. All submarines, no matter what size they are, are designated as boats.
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By Simon Smith