Undersea Special Warfare Engineering. Program Executive Office (PEO). Unmanned and Small Combatants. This coin is 2 1/2 inches in diameter. This is coin is a beauty! Never personally given any of the coins. All coins are guaranteed to be in excellent condition unless otherwise specified above. The free listing tool. The item “Undersea Special Warfare Engineering PEO SEAL Submergence Navy Challenge Coin” is in sale since Friday, June 4, 2021. 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.