After the USS William D Porter accidentally fired a torpedo at the battleship carrying President Roosevelt to the Tehran Conference during WWII, other ships began greeting the Porter by signaling “Don’t shoot, we’re Republicans.”
The Imperial Russian Navy build a circular warship. Often called “the ugliest ship ever built” it fared poorly in open water and would spin out of control when it fired its guns.
The Swedish warship Vasa, which famously sank in 1628 less than a mile into its maiden voyage, was built asymmetrically. Archaeologists have found four rulers used by the workers; two turned out to be based on Swedish feet with 12 inches. The other two used Amsterdam feet, with 11 inches.
At normal speed, it takes a fully loaded supertanker/oil tanker approximately 20 minutes to stop, they cut their engines 15 miles away from the dock.
The US Navy maintains a research vessel that is designed to be capsized vertically. As a result, most rooms on it have two doors: one to use when the ship is horizontal, another when vertical.
An intact steamboat from 1856 was excavated in 1988 under 45 feet of dirt in a farmers field. Thousands of artifacts were excavated and preserved so well that some of the food was still edible.
There is an abandoned Russian cruise ship roaming international waters.
A man in Denmark built a 40 tonne 60ft long submarine in his spare time.
The 15 largest ships in the world produce as much sulphur oxide pollution as all the cars in the world combined.