The way it works today, is that sailors park their car in the parking lot, walk up the pier to the ship, go down to their "at sea" living area and change into their uniform for the day. They stay in uniform all day during working hours. When the ship is in port, they change into their civilian clothes at the end of the day and go home to their apartment or house. Almost nobody stays in uniform for their off work time.

At sea is a different matter. It's uniform all the time then.

I've got to say though, that I would have come to work just like that lad in the picture if I could (or maybe I would have never made it)