Theodore set off to take Owan, the Oil Rig, all the way to the other side of the harbour.

Owan was the biggest, heaviest thing Theodore had ever pushed. "Ready when you are, Theodore!" called Owan cheerfully. Theodore pressed his bow against the great rig, blew out a deep breath, and pushed. Slowly, ever so slowly, Owan began to move.

Across the busy harbour they went, past the ferries and the fishing boats, with Theodore steering very carefully so that Owan never bumped into anyone. It was hard work, and Theodore's engine huffed and puffed, but he didn't stop. At last Owan was settled safely on the far side. "Thank you, Theodore!" said Owan. "You're a fine, strong tugboat." Theodore glowed with pride, even though he was very, very tired.