See website: Submarine
Virginia class submarine
David Bushnell launched what is regarded as the world's first submarine.
The world's first atomic powered submarine was the USS Nautilus.
Submarines can pump sea water into or out of ballast tanks, if they wish to change their weight (of course, anything that enters or leaves a submarine will also change its weight - people, supplies, weapons, etc. - but if you just want to change the weight, the easiest way is to pump water into the submarine).
The USS Nautilus (SSN-571) was the world's first operational nuclear submarine.
No
A U-boat was a submarine used by Germany in World War 1 and World War 2.
The submarine you are thinking about was the USS Nautilus. It was the world's first nuclear powered submarine and commissioned into the US Navy in 1955
the U boat 'is' the German word for submarine. western nations just used submarine. U boat is short for Unterwasserboot, which translates as undersea boat or under water boat or submarine.
There was no submarine that could do that as early as 1945
United States Submarine Operations in World War II was created in 1949.