Sea Captains have always been a symbol of stoic resolve and masculinity– as well as awesome mustaches & killer coats.  Photos– The Library of Congress archive.

Throughout history, mustaches have been worn by military men.  Generally, lower ranks wore smaller and less elaborate mustaches. 

As a man advanced in rank, his moustache would become thicker and bushier, until he was permitted to wear a full beard.

Mustache or moustache, they are both correct.  I’ll go with moustache from here on out.