Coast Guard is a port authority launch vessel. He often stands at the entrance to the estuary ready to question and check incoming shipping before clearance. On other occasions he stands by and over-looks large-scale operations, such as demolition and quarry work. He also doubled as a 'one-man' police-force. Despite his size, he has heavy influence and authority over the vessels of the port.
He makes numerous cameo appearances, but has minor speaking roles in the episodes High Winds, Warrior and Quarantine. In the episode High Winds, he is rammed into the rocks by Johnny Cuba, later to be found and rescued by Zebedee. He later arrested Johnny Cuba. In Warrior, he oversees the pulling down of old buildings at the old quayside. In Quarantine, he is seen quarantining and clearing ships to enter the harbour and admonishes Nantucket for having his flags down without permission and puts Zorran under Quarantine.
- Lee Cornes (TUGS)
- Paul Dobson (Salty's Lighthouse)
- Sukekiyo Kameyama (Japan)
- Elise Langenoja (Finland)
- Because of his small size, the eye and wheelhouse mechanisms could not be added to his model.
- Coast Guard's model was reused as a fishing boat in TUGS' sister show, Thomas & Friends.
- The model remained unmodified in Season 3. However, in Season 4, it was repainted light grey.