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The three "V"-shaped stripes on the upper sleeve indicate that he is a PO1 or First Class Petty Officer. Farther down on the sleeve, in the area of the forearm, are found Service Stripes (also commonly referred to as "hash marks"). You get one Service Stripe for each four-year term of completed military service. It can be mixed service, too. If you completed, say, two years of service in the Army, then transferred to the Navy and completed two more years, you'd qualify for one Service Stripe for those total four years of military service. [Check out Robert DeNiro's character, CPO Billy Sunday, in the movie "Men of Honor." He's got a huge number of hash marks on his uniform. lol]

Petty Officer 1st Class is Holman's "paygrade" in the Navy, his rating (indicated by the propeller insignia below the crow) is that of a Machinist's Mate. His full title would thus be "Machinist's Mate 1st Class."

The two service marks below indicate at LEAST eight years of service (four years per hash mark.) He mentions he has been in the Navy for nine years to Shirley on the steamboat, meaning he reenlisted just a year before the movie begins. He is definitely a World War 1 veteran.

The three stripes indicate he is a 1st Class, which was one paygrade below Chief Petty Officer, which until 1958 was the highest enlisted rating in the U.S. Navy and Coast Guard. Holman achieving 1st class in less than nine years obviously means he was pretty damn good at his job.