The Caspian Sea is also classed as the world's largest lake.
52
There was once an undersea post office in the Bahamas.
241
In 1992, 29,000 rubber ducks washed off a ship. They were found thousands of miles away 8 years later.
707
There are approximately three million shipwrecks on the ocean floor, worth billions in value and treasure.
22
Water is actually naturally blue.
48
Tidal forces between the Earth and Moon are slowing the Earth down and pushing the Moon further away.
46
The North Atlantic gets 2.5 centimetres (1in) wider every year.
119