submarine, n.Trivia

Submarines were first launched as early as 1776

Submarine sonar is no a “ping” like movies and games, but actually extremely loud and can kill people and sea life

the US Navy never considers a submarine lost if it doesn't return. It's considered to be "still on patrol".

Armadillos can walk underwater

The British submarine HMS Trident had a fully grown reindeer onboard as a pet for six weeks during WWII.

US Navy replaced expensive and clunky periscope controls on submarines with Xbox 360 controllers, which reduced training time from hours to minutes.

Pepsi was once the 6th largest military power in the world for a short time when the Soviet Union traded the company 17 submarines, a cruiser, a frigate, and a destroyer for Pepsi to be sold in the Soviet Union

Hippopotamuses are born under water

Kaiten were manned torpedos used by the Japanese in WWII. They were basically underwater Kamikaze.