I hate to quibble, but in the Navy rate and rank are two different things. Rank is paygrade -- E4, O3, etc., while rate is one's occupational specialty -- Fire Control Technician, Boatswain's Mate, Hull Technician, Boiler Technician, etc.
Thus, an HT2 is a hull technician second class, a second-class petty officer (E5) who is a hull technician, and an HT1 is a hull technician first class, a first-class petty officer (E6) who is a hull technician.
HTFR
HTFA
HTFN
HT3
HT2
HT1
HTC
HTCS
HTCM
An excellent quibble. (LOL!) Actually, I got that from a website that has an unofficial Marine dictionary. Rate/Rank is pretty confusing to me. (I don't know if you saw, but we recently did a thread each for Commissioned and Enlisted ranks.) Thanks for your input!!