The North Atlantic gets 2.5 centimetres (1in) wider every year.
119
The Caspian Sea is also classed as the world's largest lake.
52
Sea otters hold hands while sleeping so they don’t drift away from each other.
104
More than a dozen men have stood on the surface of the moon, but only three have been to Challenger Deep in the Marianas Trench, the deepest known spot in the ocean.
17
Water is actually naturally blue.
48
There are approximately three million shipwrecks on the ocean floor, worth billions in value and treasure.
22
Sharks, like other fish, have their reproductive organs in their chests.
248
Two dogs were among the Titanic survivors.
262