Short answers, pulled from the story.
There is no universally accepted distinction between a ship and a boat. A common notion is that a ship can carry a boat but not the reverse, and a US Navy rule of thumb holds that ships heel toward the outside of a sharp turn while boats heel toward the inside. Ships are generally larger and can remain at sea for longer periods than boats.
Ship transport is responsible for the largest portion of world commerce. In 2024, ships had a global cargo capacity of 2.4 billion tons, with dry bulk carriers at 43 percent, oil tankers at 28 percent and container ships at 14 percent.
Richard Woodman recognizes the Phoenicians, who were building large merchant ships by 1200 BC, as the first true seafarers. He credits them with founding the art of pilotage, cabotage and navigation, and with building the first true ship made of planks, capable of carrying a deadweight cargo and being sailed and steered.
The Plimsoll mark is a line on a ship's hull indicating its maximum safe loading level, consisting of a circle with a horizontal line through the center. It originated with Samuel Plimsoll's Merchant Shipping Act of 1876 in Britain and is replaced by a diamond on the Great Lakes of North America.
Steam ships replaced sailing ships as engine efficiency improved through the 19th century. Higher boiler pressures of 60 psi powering compound engines, introduced in 1865, made long-distance steam cargo viable from England to China even before the Suez Canal opened in 1869, and triple-expansion engines running at 125 psi in SS Aberdeen in 1881 made nearly all routes competitive.
Ships pollute through oil spills, ballast water and exhaust emissions. An oil tanker can carry 2 million barrels of crude, the Exxon Valdez spilled 10.8 million US gallons in March 1989, ballast water has spread invasive species like the comb jelly Mnemiopsis leidyi into the Black Sea, and seagoing vessels account for an estimated 14 percent of nitrogen and 16 percent of sulfur emissions from fossil fuels into the atmosphere.