The term is beginning to find some usage amongst the civilian population as well, usually after someone has volunteered him or herself to do something, only to have it turn into a giant pain in the ass that you can't get out of.
Regardless of the particular context, the term is always used while bitching about something.
Steven: Navy, dude. Navy.
Johnny: Yup. Navy.
You also sometimes hear it as a direct substitute for words like shitty, sucks, bullshit, etc.
Example: Johnny: This is so fucking Navy!!
The Navy is full of smart, strong and brave men and women.
Provides long-range, heavy artilery fire for land and amphibious units
Provides forward operations and launch point for aircraft
Transports those damned Marines
And need I mention the SEALs and SWCCs?
Their role in combat operations will likely only continue to increase as everyone loves a "clean" air war. However, because they do not have a true ground force anymore they are not self-sufficient and must work very closely with the Army/Marines during combat operations.