Small boats are typically found on inland waterways such as rivers and lakes, or in protected coastal areas. However, some boats, such as the whaleboat, were intended for use in an offshore environment. In modern naval terms, a boat is a vessel small enough to be carried aboard a ship. Anomalous definitions exist, as bulk freighters 1,000 feet (300 m) long on the Great Lakes being known as oreboats.
Boats vary in proportion and construction methods due to their intended purpose, available materials, or local traditions. Canoes have been used since prehistoric times and remain in use throughout the world for transportation, fishing, and sport. Fishing boats vary widely in style partly to match local conditions. Pleasure craft used in recreational boating include ski boats, pontoon boats, and sailboats. House boats may be used for vacationing or long-term residence. Lighters are used to convey cargo to and from large ships unable to get close to shore. Lifeboats have rescue and safety functions.
Boats have served as transportation since the earliest times. Circumstantial evidence, such as the early settlement of Australia over 40,000 years ago, findings in Crete dated 130,000 years ago, and 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 dugouts, and the oldest boats found by archaeological excavation date from around 7,000–10,000 years ago. The oldest recovered boat in the world, the Pesse canoe, found in the , is a dugout made from the hollowed tree trunk of a Pinus sylvestris that was constructed somewhere between 8200 and 7600 BC. This canoe is exhibited in the Drents Museum in Assen, 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. Uru craft originate in Beypore, a village in south Calicut, Kerala, in southwestern India. This type of mammoth wooden ship was constructed solely of teak, with a transport capacity of 400 tonnes. The ancient Arabs and Greeks used such boats as trading vessels.