Please forgive me if any of my terminology is incorrect. Being a captain of a ship---especially a large one---is a great responsibility. It's my understanding that the captain is responsible for all personnel, all departments, and the overall safety and performance of his ship. So say when a young ensign graduates---are they assigned a permanent career job specialty? Or does his specialty depend on his assignment? Do they receive training for all different things or is it all OJT-type training? It seems logical to me that a ship's captain would, over the course of his career, would be given at least a small amount of experience in all departments aboard a ship. Example---"Before I was given the ship's command off USS D, I was the navigation officer on USS A. I was the weapons officer on USS B. I was a power-plant officer on USS C.", etc. Does this make any sense? Thank you in advance.