One-Of-Kind, Navy CPO Challenge Coin, USS Gridley. The item “One-Of-Kind, Navy CPO Challenge Coin, USS Gridley” is in sale since Friday, July 12, 2019. This item is in the category “Collectibles\Militaria\Current Militaria (2001-Now)\Original Items\Challenge Coins”. The seller is “kreativeguy1980″ and is located in Norfolk, Virginia. This item can be shipped to United States.