shooting pool with the Captain

What is shooting pool with the Captain?

shooting pool with the Captain meaning in Military or Military Slang terminology / glossary / dictionary is:
(U.S.) A U.S. Navy term for captain’s mast (non-judicial punishment presided by the unit commanding officer) . This refers to the green felt cloth draped over the commanding officer’s table during mast. The green cloth is a tradition dating to the Royal Navy in the 15th century that is symbolic for the Captain’s mastery of the seas.

 

reference: Glossary of military slang