Oliver the Vast is a tugboat from another harbour with a blue cap.
Oliver is a large ocean tug, brought to the Big Harbour to help move Owan. He is disliked by both George and Owan because of of how mean-spirited and nasty he is, and especially took pleasure in bumping and bullying Theodore, no matter how hard Theodore tried to be friends with him. George's hatred toward Oliver only grew when he saw him bullying Theodore. Eventually, Theodore told the Dispatcher, who sent Oliver home in disgrace.