The first submarine was built in 1620 to harvest coral from the ocean. Nearly 400 years ago! That is before cars and telephones were invented!
Most Navy forces employ submarines today as they are mostly used for military or scientific purposes.
Submarines are able to control their density, allowing them to choose whether to sink or float at a particular time.
There are many types of submarines available ranging from small 2 person submarines that can stay under water for a few hours, or those that are large enough to carry nuclear weapons and stay underwater for months!
Most Navy forces employ submarines today as they are mostly used for military or scientific purposes.
Submarines are able to control their density, allowing them to choose whether to sink or float at a particular time.
There are many types of submarines available ranging from small 2 person submarines that can stay under water for a few hours, or those that are large enough to carry nuclear weapons and stay underwater for months!