Naval Special Warfare Gp 3. Condition : Used and in good condition. This coin is 2 inches in diameter. 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 “Naval Special Warfare Gp 3 Training DET-3 Hawaii SEAL Navy Challenge Coin” is in sale since Wednesday, September 27, 2017. 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.