That's the bosun locker tag. I've been bosuns mate on several yachts over the years, and its a great job. The bosuns mate is in charge of the maintenance of the ship/yacht. His duties are to direct and manage the crew in the daily chores of the ship. He is also in charge of the ships stores, and supplies involved in the daily working of the ship. One of the responsibilities is to keep the bosuns locker stocked and provisioned for long journeys. Items could range from paints and varnishes, to chains, ropes, and fenders. All manner of ships supplies would be stored in the bosuns locker. I had a whole room with a separate out door entrance on the big westPort yachts. This large room had a gullwing door in the main deck in the bow of the boat, it was roomy and air-conditioned and I considered it my office. Bosuns mate is an officers position and pays well.....bosun mate is in charge of most of the crew, and makes up the daily work schedule for most of the crew !!
The tag you've found is off the door to the bosuns locker/room.
