Special Boat Team SBT-12 Coastal Troop Three CT-3 PLTs I J K Navy Challenge Coin Posted on February 25, 2024 by admin Naval Special Warfare Group 4. Special Boat Team / SBT-12. Coastal Troop Three / CT-3. I / J / K. Condition : Used and in nice shape. This coin is 1 5/8 inches in diameter.