This is a jacket patch, given to the crew members of the Pledge, in the shape of a shield. 
The background is light blue with a black border. 
At the top are the letters "USS". Below that is a picture of a 
black bottom mine with the silver number 73 in the middle representing 
the Mine Division the Pledge was in. Behind the mine is a crossed sword and 
lightning bolt. Below the mine is the word Pledge.