The design of the earliest boats is open to debate. They could have been dugout canoes, bark canoes, or animal skin boats. Dugouts were made from a single log. A large hollow area was burned and carved out of a tree trunk permitting a passenger to be seated. Planks added to the sides to keep out water may have been the inspiration for plank construction. Wooden outriggers added to the right or left side of canoes were a later innovation that helped prevent capsizing. Animal skins were also used in early forms of boats. Sewn hides were stretched over a wooden frame, sewn together, and sealed with pitch. Such a boat was light and easy to carry. Surviving Assyrian relief carvings from 700 BC show skin covered boats being used to transport chariots across the Euphrates River.
Many early boat innovations originated in Egypt. The Nile flowed north but the prevailing winds blew south. The wide and peaceful Nile was thus a natural water highway, encouraging the use of boats. The Egyptians are credited with inventing sails. They used first plants or leafy branches to catch the wind. By 3500 BC they were employing a square sail, probably woven of reeds and set on a single vertical mast placed in the bow. Between 2200 BC and 1900 BC the position of the mast migrated from the bow to amidships. This made it possible to drive the boat forward using cross winds, not just tail winds. The need to transport large stone blocks down river for monument building may have spurred the conversion from reed boats to wooden plank hulls.
The transition from the paddle to the oar took place in Egypt around 2500 BC. The oar had several advantages over the paddle and permitted both the size and speed of vessels to increase. The oar was secured to the boat, giving the oarsman more leverage. It also permitted multiple rowers to be placed side-by-side manning a single oar, although this innovation was not adopted until centuries later. The deck of the traditional paddle boat needed to be low to the waterline so the paddles could reach the water. This restriction had limited the overall size, height, and displacement of boats of that time. Long oars made larger boats possible.
Oversized oars dipped into the water near the rear of the boat were used to steer. This early rudder was first simply held by the helmsman and not connected to the boat. Large vessels of the time had as many as five steering oars.
Exploration of more than 30 ancient wrecks found around the Mediterranean revealed that the ancient ship builders started from the outside and built in, rather than starting from the inside and building out, as is done today. Rather than build a frame and then add planking, the ancients build a frame first and stiffened it with inside supports. Mortises (wide holes) were drilled into the edges of hull planks and a wooden tenon (plug) was inserted into the mortises of two adjacent planks. The tenon was half inside each plank and held in place by wooden dowels that went through the planks and tenons. Swelling of the planks, dowels, and tenons sealed the joints without need for caulking. The frame was then stiffened with cross bracing and decks.
The oldest sailing ship of mortise and tenon construction is a wreck from 1350 BC found off the coast of Asia Minor. The earliest record of sailing ships is a tomb painting from Thebes dating to 1400 BC. This painting shows merchant sailing ships from the Levant arriving in Egypt. The ships are being unloaded down gangplanks from the ship to the beach.
Greek and Phoenician sea trading blossomed in the Eastern Mediterranean starting around 900 BC. Both groups established colonies around the Mediterranean and built trading empires. The Phoenicians were perhaps the finest sailors of antiquity, certainly ranging as far as Britain for the crucial metal tin. There is some evidence that Phoenicians circumnavigated Africa and perhaps reached the Americas.
Phoenician ships had hulls of a broad beam and were rounded at both stem and stern. They usually carried a carved horse’s head on the prow. Greek writers called these ships "tubs" for their shape or "horses" because of their figurehead.
The early sails had a boom across the bottom, as used by the Egyptians on the relatively peaceful Nile. By the sixth century, the broad, loose-footed square sail was in general use on the open sea where it was more practical. The evidence of an Etruscan tomb painting from Tarquinia, Italy, circa early fifth century BC, shows merchant ships were using two masts and a foresail by that time.
By at least the fifth century BC, merchant ships of 400 ton capacity were carrying the large bulk cargoes in the Mediterranean. Modern merchant ships larger than this were not built until the nineteenth century AD. The most important bulk cargoes at this time were grain, wine, and olive oil.
The largest known merchant ship of ancient times was built for Hiero II, king of Syracuse 270-215 BC, to carry grain from Egypt. It carried three masts and required a bilge pump designed by the famous ancient engineer Archimedes. The cargo on its maiden voyage included 60,000 measures of grain, 10,000 jars of preserved Sicilian fish, 20,000 talents of wood, and 20,000 talents of miscellaneous goods. This cargo weighed 2,000 tons by modern estimates. In the event that the king wished to accompany a voyage, the ship was also equipped with luxury accommodations, including cabins with mosaic floors, promenades decorated with plants, a gymnasium, a bath room fitted with copper tubs and marble basins, a library, and a chapel to Aphrodite.