master mariner

plural master mariners

1. nauticalA seaman who has qualified to be a captain of a merchant ship

   1987, D. J. House, Seamanship Techniques, Volume 2, chapter heading, Certificate of Competency for Master Mariner, Class 1

   2 more examples

   That B. C. S., late, &c., master mariner, on, &c., at a foreign port or place called Valparaiso, in South America, then and there being the master and commander of the "Henry Clay," ...

   1849, Francis Wharton, Precedents of Indictments and Pleas

   1901, Joseph Conrad, Falk: A Reminiscence, He was a Schiff-fuhrer: Ship-conductor. That's how they call a Master Mariner in Germany. I prefer our way. The alliteration is good, and there is something in the nomenclature that gives to us as a body the sense of corporate existence: Apprentice, Mate, Master, in the ancient and honourable craft of the sea.