A wooden boat operating near shore. A boat is a watercraft designed to float or plane on water, and provide transport over it. Usually this water will be inland (lakes) or in protected coastal areas. However, boats such as the whaleboat were historically designed to be operated from a ship in an offshore environment. In naval terms, a boat is something small enough to be carried aboard another vessel (a ship). Some boats too large for the naval definition include the Great Lakes freighter, riverboat, narrowboat and ferryboat. Modern submarines can also be called boats, despite their underwater capabilities and size. This may be because the first submarines could be carried by a ship and were not capable of making independent offshore passages. Boats may be used by the military or other government interests, or for research or commercial purposes; but regardless of size, a vessel in private, non-commercial usage is almost certainly a boat. See also: Glossary of nautical terms and Naval architecture

A boat in an Egyptian tomb painting from about 1450 BCE The roughly horizontal, but cambered structures spanning the hull of the boat are referred to as the "deck". In a ship there are often several, but a boat is unlikely to have more than one. The similar but usually lighter structure which spans a raised cabin is a coach-roof. The "floor" of a cabin is properly known as the sole but is more likely to be called the floor. (A floor is properly, a structural member which ties a frame to the keelson and keel.) The underside of a deck is the deck head. The keel is a lengthwise structural member to which the frames are fixed (sometimes referred to as a backbone). The vertical surfaces dividing the internal space are bulkheads. The front of a boat is called the bow or prow. The rear of the boat is called the stern. The right side is starboard and the left side is port. Boats of earlier eras often featured a figurehead protruding from the front of the bows.