NSWG-4 Special Boat Team SBT Dirty Boat Guys DBG Chief / CPO Navy Challenge Coin Posted on March 28, 2025 by admin Naval Special Warfare Group 4. Special Boat Team(s). Dirty Boat Guys / DBG. Chief’s Mess / CPO. Condition : Used and in nice shape. This coin is approximately 4 inches wide by 1 1/4 inches high.