Submarines are designed with enough ballast and control systems to allow them to submerge and surface as needed.
Surface ships are designed only with enough ballast and control systems to keep them on the surface. While they can sink just as well as submarines can, their ability to re-surface without a salvage operation is non-existent.
Ships try to avoid sinking, submarines sink on purpose...
They caused anxiety and sink ships.
Ships don't sink because they are more boant then the water they float on. Ships don't sink because they are more boant then the water they float on.
sink allied supply ships to England
They were at war with each other.
To sink enemy vessels, ships or submarines.
Because they don't sink.
They were used mainly to sink enemy transport ships.
To stop supplies from reaching England
Ships float because they displace enough water to create an upward force called buoyancy that is greater than their weight. Coins sink because they are denser than water and therefore displace less water than their own weight.
IJN & USN subs went looking for ships to sink.
They rise to the surface when air is pumped IN. They sink when air is let out