Boatswain Mates are part of the Deck Division. They stand watches at the helm and lookouts. They are responsible for the outside of the ship. They also maintain the small boats and top side equipment as well as provide boat crews.
It Is the Navy Enlistment Code (NEC) meaning you are still a trainee. Sometimes that NEC never changes til you make NCO (E-5 or above). The BM portion stands for Boatswains Mate or Petty Officer. This is for E-4 thru E-6.
The Navy Boson's mate is the Captain.... the Boson is the second in command...
Gunners Mate Master Chief
The rate/rank designator MMCS is a Senior Chief Machinist's Mate (E-8). Read in its correct Navy form, it stands for "Machinist's Mate, Chief, Senior".
The oldest rating in the United States Navy of those that are currently active is the Boatswain's Mate.
carpenter's mate first class
For the U.S. Navy it means Interior Communications Mate Second Class.
Yes it is but, it should be your last resort.
GM Gunners Mate (Navey) GI General Issue (Army)
That would be extremely difficult to determine but for your consideration the Medal of Honor in WWI was awarded to Sydney G. Gumpertz, First Sergeant, US Army, Phillip C. Katz, Sergeant, US Army, Benjamin Kaufan, First Sergeant, US Army and William Sawleson, Sergeant, US Army, and a single individual from the US Navy, John Otto Siegel, Boatswains Mate Second Class.
Pay rates in the Navy are dependant upon the rank and length of service, not on the rating. A Machinist Mate gets the same as an Electronic Technician.
Bosun's mate is a Naval job.