Underwater is a term describing the realm below the surface of water where the water exists in a natural feature (called a body of water) such as an ocean, sea, lake, pond, or river. Three quarters of the planet Earth is covered by water. A majority of the planet’s solid surface is abyssal plain, at depths between 4,000 and 5,500 metres (13,000 and 18,000 ft) below the surface of the oceans.
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