Replying to the discussion about midshipmen above:
We're in a strange gray area. I've been looking everywhere in the Regulations for Officer Development and summer training handbooks but I can't find a definitive answer about where Midshipmen lie in the rank structure.
My XO (a Commander, USN) said that Midshipmen lie above enlisted but below warrant officers and officers. But don't let this get to your head and think that we get to be called Sir and get salutes and all that. It just means that, as
03USMC said, we are officers in training and are to be treated as such.
We don't get screamed at like how a SNCO would treat a private, but we do not receive the honors of real officers, because we are not commissioned. However, we are held to a higher standard of conduct and are not allowed to overly fraternize with the enlisted, like an officer.
What c/Commander said about being treated like an officer as a 1/C is sort of true... sort of. Specifically, on your 2/C cruise you experience the life of an enlisted, eating in the enlisted spaces, sleeping in an enlisted bunk, etc. But as a 1/C, you experience the life of an officer, eating in the wardroom, following a JO around, etc. But you are NOT an officer, you are NOT a 'sir', you just get to play pretend.
Besides, if someone wants to become an officer just so people salute them and call them sir, I suggest they find a different career. There's more to it than a power trip.