Colchester is a container ship Theodore and Emily helped bring into the harbour when Hank was suffering from hiccups. He also appears during Theodore's birthday party and when Theodore had his backwards problems. He is a big, bold green-hulled container ship from the United States of America, and is easily one of the biggest ships ever to tread water in the Big Harbour.
- Season 3 - Hank's Hiccups (not named), Hank's New Name (cameo), Big Harbour Birthday (cameo), and Theodore's Backwards Day (cameo)
- Colchester apparently uses the same model as Cumberland.
- Colchester's small-scale model was offered for sale on eBay but was later donated to the Colchester County Museum in Truro, Nova Scotia.