Gustavo 'Tavo' Barros is the supreme leader and Chancellor of the Gran Colombian Empire. His army is behind the cyber attack against the United States and the destruction of their Naval fleet. His control spreads beyond Colombia and reaches throughout South and Central America. He set his conquest on the United States and any Latin nation that refuses his protection.
He is not native Colombian since Hector Martinez reminded him he did not speak Spanish well, when he arrived to Colombia.
After his forces are defeated and his army surrenders, Barros is confronted by Danny Green and Sasha Cooper who demand his surrender. Barros refuses to surrender to anyone but Tom Chandler "soldier to soldier." After Barros goes for a gun when they refuse, Green and Cooper shoot him dead in self-defense.
- Barros is the final main antagonist in The Last Ship as well as the final on-screen death though the crew of Gustavo's Battleship died shortly after him.