In American naval slang, submarines are the only vessels referred to as "boats", whereas surface vessels are colloquially referred to as "ships".

Anechoic tiles are rubber-like tiles containing thousands of tiny voids, applied to the outer hulls of military ships and submarines. The technology of anechoic tiles was developed by Germany in the Second World War. After the war it was not used until the 1970s when the Soviet Union began coating its submarines in rubber tiles. Modern Russian tiles are about 4 inches thick, and apparently reduced the acoustic signature of submarines to 10% to 1% of its original strength. The US Navy began applying a similar coating to its submarines in 1988, and navies around the world quickly followed suit.

USS Nautilus (SSN-571) was the world's first operational nuclear-powered submarine and the first vessel to complete a submerged transit across the North Pole. During testing she traveled from New London to San Juan, Puerto Rico and covered 2,223 km (1,200 nmi) in less than ninety hours. At the time this was the longest submerged cruise by a submarine and at the highest sustained speed (for at least one hour) ever recorded. The improvements rendered the progress made in anti-submarine warfare during the Second World War virtually obsolete.

The first tank was developed by the British in World War I as a solution to the trench warfare stalemate. The first prototype of the Mark I tank was tested for the British Army on September 6, 1915. To preserve secrecy the initial vehicles were referred to as "Water-carriers". The workers of were given the impression that they were building "Water-carriers for Mesopotamia"; hence the name Tank.

On July 28th 1945, a United States B-25 bomber, flying in heavy fog, crashed into the 79th and 80th floor of the north side of the Empire State Building. 11 people in the building, and all 3 crew men on the bomber were killed.