NYC's Metropolitan Transit Authority (MTA) dumps old subway cars into the ocean to serve as artificial reef.
8
There was once an undersea post office in the Bahamas.
241
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
Tidal forces between the Earth and Moon are slowing the Earth down and pushing the Moon further away.
46
The Caspian Sea is also classed as the world's largest lake.
52
There are approximately three million shipwrecks on the ocean floor, worth billions in value and treasure.
22
Water is actually naturally blue.
48
If Antarctica's ice sheets melted, the worlds oceans would rise by 60 to 65 metres (200 - 210ft) - everywhere
181