The record for the deepest free dive is held by Jacques Mayol. He dove to an astounding depth of 282 feet without any breathing equipment.
The deepest spot on Earth, Challenger Deep, is 35,802 feet (11,034 m) deep. It is found in the Mariana Trench, one of the many deep valleys of the Pacific Ocean. The pressure here is over 8 tons per square inch.
Movie director James Cameron ventured to 12,378 feet below the surface of the Atlantic, in a submersible with a nine-inch-thick porthole, to film the movie "Titanic."
The highest tides on Earth are found in the Bay of Fundy east of New Brunswick, Canada. The channeling effect of the bay is responsible for the amazing difference between high tide and low tide, which, during spring tides, can reach 53.5 feet. This is almost as tall as a four-story building.
Amazing Features of the Ocean Floor
The longest mountain range on Earth is really the Mid-Ocean Ridge. It extends from the Arctic Ocean, down the middle of the Atlantic, winding into the Pacific Ocean.
The largest waterfall on Earth is actually underwater. It is found in the Denmark Strait, and slowly cascades downward for 2.2 miles. This is over three times as tall as Angel Falls, in Venezuela, which is the tallest land waterfall.
The tallest mountain on Earth is also (you guessed it!) partly underwater. Mauna Kea, an inactive volcanic island in Hawaii, stands 33,465 feet tall when measured from ocean floor to summit.
The elements oxygen and hydrogen are 96.5% of ocean water. The other 3.5% is dissolved elements, such as chlorine, sodium, and other salts.
About 97% of all of the Earth's water is saltwater.
The oceans cover about 71% of Earth's surface.
The thermocline is an ocean zone in which the temperature drops very rapidly. It is usually found at around 300 to 800 meters deep, between the relatively warm surface zone and the cold deep zone. The thermocline blocks sonar, so it is a favorite hiding place of submarines.
The temperature of most ocean water is about 39 degrees Farenheit (4 degrees Celsius), which is just above freezing!