There are now 'Attack' submarines who's main purpose is to sink enemy submarines and ships and also Missile submarines whose main purpose is to launch ballistic missiles at the enemy.
John P. Holland is credited with inventing the first modern submarine and is considered the father of modern submarines.
to control the buoyancy of a submarine
The submarine had been envisioned by ancients as a weapon to be used against surface ships. Hundreds of years went by before technology allow construction of one. The "real" boats were around in a limited way in WWI, but by WWII, they kicked butt. Today, we have superb military submarines. The submarine was also seen as a research vessel and a recreational vehicle before they advent of the "real" submarine.
What is the basic purpose of insurance
In war a submarine can hide under the water and attack without being seen.
yes
basic purpose and function of an independent laboratory
He is the Inventor of the Modern Submarine.
Modern Submarines do not have a keel like other ships....
WWII boat shaped bows; nuclear subs have cigar shaped hulls.
Harry S. Truman
to keep the sub level or help it to dive and surface