NYC's Metropolitan Transit Authority (MTA) dumps old subway cars into the ocean to serve as artificial reef.
8
There are approximately three million shipwrecks on the ocean floor, worth billions in value and treasure.
22
The Caspian Sea is also classed as the world's largest lake.
52
There was once an undersea post office in the Bahamas.
241
It's impossible to sink in the Dead Sea without equipment!
72
If Antarctica's ice sheets melted, the worlds oceans would rise by 60 to 65 metres (200 - 210ft) - everywhere
181
Two dogs were among the Titanic survivors.
262
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