A submarine (sub) is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. It is also sometimes used historically or colloquially to refer to remotely operated vehicles and robots, as well as medium-sized or smaller vessels, such as the midget submarine and the wet sub. Submarines are referred to as "boats" rather than "ships" irrespective of their size.<br /><br />The Guide To Submarines<br />https://engineers-channel.blogspot.com/p/the-guide-to-submarines.html<br /><br />Submarines<br />https://engineers-channel.blogspot.com/p/submarines.html
