SEA

• https://en.wikipedia.org/wiki/Sea
• The sea, the world ocean or simply the ocean is the connected body of salty water that covers over 70% of Earth's surface (361,132,000 square kilometres (139,434,000 sq mi), with a total volume of roughly 1,332,000,000 cubic kilometres (320,000,000 cu mi)).
• ^[1] It moderates Earth's climate and has important roles in the water cycle, carbon cycle, and nitrogen cycle.
•  It has been traveled and explored since ancient times, while the scientific study of the sea—oceanography—dates broadly from the voyages of Captain James Cook to explore the Pacific Ocean between 1768 and 1779.
•  The word sea is also used to denote smaller, partly landlocked sections of the ocean and certain large, entirely landlocked, saltwater lakes, such as the Caspian Sea and the Dead Sea.
• see the Atlas or the map and find where is Caspian Sea and Dead Sea.
• Find our why is it called the Dead Sea.
• Our oceans cover more than 70 per cent of the Earth's surface. ...
• The majority of life on Earth is aquatic. ...
• Less than five per cent of the planet's oceans have been explored. ...
• The world's longest mountain chain is underwater. ...
• There are more historic artefacts under the sea than in all 
• The Seven Seas include the Arctic, North Atlantic, South Atlantic, North Pacific, South Pacific, Indian, and Southern Oceans. The exact origin of the phrase 'Seven Seas' is uncertain, although there are references in ancient literature that date back thousands of yearsof the world's museums.
• Why is the sea BLUE?
• The ocean is blue because water absorbs colors in the red part of the light spectrum.
•  Like a filter, this leaves behind colors in the blue part of the light spectrum for us to see. 
• The ocean may also take on green, red, or other hues as light bounces off of floating sediments and particles in the water.
• "The ocean looks blue because red, orange and yellow (long wavelength light) are absorbed more strongly by water than is blue (short wavelength light).
•  So when white light from the sun enters the ocean, it is mostly the blue that gets returned. Same reason the sky is blue."
• https://youtu.be/iX5xDRJvnxc