Jest to bardzo ciekawe (pominę polskie tłumaczenie filmu) i jeżeli ktoś ma ochotę pogłębić wiedzę:
1) The title, originally "master and commander," originated in the 18th century to describe naval officers who commanded ships of war too large to be commanded by a lieutenant but too small to warrant the assignment of a post-captain and (before about 1770) a sailing-master; the commanding officer served as his own Master. In practice, these were usually unrated sloops-of-war of no more than 20 guns.
2) a w innym miejscu znalazłem ten ciekawy artykuł: https://www.dailywritingtips.com/captain-vs-master/