A Navy rule of thumb says ships and boats lean opposite ways
No agreed line separates a ship from a boat, but sailors have tests. One says a ship can carry a boat and never the reverse. A US Navy rule of thumb says that in a sharp turn a ship heels outward and a boat heels inward, because of where each keeps its centre of mass relative to its centre of buoyancy.
The word itself shifted. From the mid-18th century, sailing vessels were classified by rig rather than hull shape, and a ship in the strict sense meant a vessel with three or more masts, all square-rigged, while the looser sense of any big seagoing craft carried on alongside. Some large vessels keep the humbler name anyway, most famously submarines, along with Great Lakes freighters and ferryboats. English also kept calling ships she, a habit the Imperial War Museum links to older traditions of a protective mother or goddess figure, though Lloyd's Register switched to it by 2019.
Boats appear in Egypt in the 4th millennium BC. Around 2500 BC a 44-metre vessel was buried beside the Great Pyramid for Khufu and found intact in 1954. By 1200 BC Phoenicians were building large plank-hulled merchant ships able to carry heavy cargo and be steered, and the maritime historian Richard Woodman credits them with founding the arts of pilotage and navigation.
Some ancient ships were huge. In the 2nd century AD, builders from the Indonesian archipelago made vessels over 50 metres long with four to seven masts, able to carry 600 to 1,000 people and sail against the wind. Chinese sources called them kunlun bo, and they may have reached as far as Ghana. China's early ships, including stern-mounted rudders from the 1st century AD, served rivers; it adopted seagoing designs only in the Song era after meeting those Southeast Asian traders. In 1350 the Javanese Majapahit empire sent about 400 large jong transports against Pasai.
Ships still move most of the world's trade. In 2024 the global fleet could carry 2.4 billion tons, with dry bulk carriers making up 43 percent, oil tankers 28 percent and container ships 14 percent.
Source: Ship
