Greenert Chief of Naval Operations. Condition: Used, but in nice shape. The coin is 1 3/4 inches in diameter. To view miscellaneous challenge coins. NOTE: Never personally given any of the coins. All coins are guaranteed to be in excellent condition unless specified above. The free listing tool. The item “Vice Admiral Jonathan W. Greenert Chief of Naval Operations Navy Challenge Coin” is in sale since Friday, March 14, 2014. This item is in the category “Collectibles\Militaria\Current Militaria (2001-Now)\Original Items\Challenge Coins”. The seller is “rolyat11″ and is located in Panama City, Florida. This item can be shipped worldwide.