The proper term is Submariner, and the proper pronunciation is "Sub-ma-reen-er". Using the pronunciation "Sub-mare-a-ner" will get you a nasty look at best, a smack upside the head at worst.
Old slang terms in the Navy are also "Bubblehead" and "Pig Boat Sailor" (from the old days of WW1/WW2 diesel boats with limited water supplies).
He is a submariner.
ummmm i think its a sailor!
Tech Person
a slave
Employee
someone who works for a business
A mathematician
moofer
An employee.
Landscaper
A vulcanologist.
keelman