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 “Admiral Vern Clark Chief Naval Ops Navy Challenge Coin” is in sale since Monday, September 03, 2012. 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.