Very Rare, Guantanamo Bay, NAVY Ball 2018 Challenge Coin. The item “RARE2018, Guantanamo bay, NAVY BALL, CPO COIN” is in sale since Monday, September 24, 2018. This item is in the category “Collectibles\Militaria\Current Militaria (2001-Now)\Original Items\Challenge Coins”. The seller is “navyjasonpr1″ and is located in Jacksonville, Florida. This item can be shipped to United States.