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Boat

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What is Boat?

A boat is a vehicle used to travel on water. It is smaller than a ship and can be lifted out of the water and carried on a ship. Some boats have sails, some are powered by rowing with oars, and some use motors.

These boats are usually made of wood. However, some parts are made of metals like steel and aluminium. Expensive boats may have parts from fiberglass or composite materials and some even have helicopter pads. There are some boats that can even go underwater. They are called submarines.

Boats have a wide variety of shapes, sizes and construction methods due to their intended purpose, available materials or local traditions. Canoe-type boats have been used since prehistoric times and various versions are used throughout the world for transportation, fishing or sport. Fishing boats vary widely in style partly to match local conditions.

 

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History of Boat:-

Circumstantial evidence, such as the early settlement of Australia over 40,000 years ago, findings in Crete dated 130,000 years ago, and findings in Flores dated to 900,000 years ago, suggest that boats have been used since prehistoric times. The earliest boats are thought to have been longboats, and the oldest boats found by archaeological excavation date from around 7,000–10,000 years ago. The oldest recovered boat in the world is the Posse canoe, a dugout made from the hollowed tree trunk of a Pinups Silvestre’s and constructed somewhere between 8200 and 7600 BC. This canoe is exhibited in the Dents Museum in Assent, Netherlands. Other very old dugout boats have also been recovered. Rafts have operated for at least 8,000 years. A 7,000-year-old seagoing reed boat has been found in Kuwait. Boats were used between 4000 and 3000 BC in Sumer, ancient Egypt and in the Indian Ocean.

Boats played an important role in the commerce between the Indus Valley Civilization and Mesopotamia. Evidence of varying models of boats has also been discovered at various Indus Valley archaeological sites. Uri craft originate in Bayport, a village in south Calicut, Kerala, in southwestern India. This type of mammoth wooden ship was constructed using teak, without any iron, and had a transport capacity of 400 tonnes. The ancient Arabs and Greeks used such boats as trading vessels.

The historians Herodotus, Pliny the Elder and Strabo record the use of boats for commerce, travel, and military purposes.

 

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How do boat float?

The weight of an object pulls it down into water. It displaces or pushes water aside. But if the object’s density (its weight in relation to its size) is less than the density of the water it displaces, it will float. That principle explains why a heavy wooden raft can float in water, while a small stone will sink to the bottom: the raft spreads its weight over a large area, while the stone’s weight is concentrated. Boats, which are hollow, float because of this principle. The air inside them makes them less dense than they appear. Large ships that transport heavy material, though, have less air inside when they are carrying a big load. Such ships must be careful about weight limits and have load lines on their hulls that show how low they can ride in the water and still manoeuvre safely. Weight limits vary with the kind of water the boats are traveling through: they can carry more weight when in saltwater seas, which are denser than freshwater, and in cold water, which is denser than warm water.

 

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