1/72 GATO QUESTION.

Not coming back from sea trials,  its coming back from a patrol.  

Its a symbol of a clean sweep.  All torpedos launched, all torpedos hit.

IIRC, there is a broom on the Silversides in Manitowoc, WI.  Revell took much of their mesaurements & details from that museum ship since its close to the Revell USA headquarters in Illinois.  

Adding the broom to the mast head is a personal choice

 When one of our 688s returned from Operation Iraqi Freedom, I don't remember which boat, she had the broom lashed to the mast indicating that all of the cruise missiles she launched hit their designated targets.   I should say so!

 I believe that the tradition is that the broom denotes that all of the targets attacked were destroyed, not so much that all of the torpedoes actually hit the target.