Pugwash is a mini-submarine who travels the world with Stewiacke taking underwater photos while Stewiacke explores the coasts.
Pugwash dreams of being a brave explorer and photographing the ocean's depths herself, but now has to overcome her fears of foghorns and lighthouses. Pugwash also loves to wander off and explore things. Her name means (Deep Water). Pugwash is also a busy, bustling little mini-sub, who enjoys hard work and hardly grumbles. Although susceptible at times, she’s a kind mini-sub and always proves her worth by being a happy little worker.
- Originally, she was going to be called Sophie.
- A spin-off to Theodore Tugboat, which would be called Pugwash's Underwater Adventures, was never made.
- Pugwash's model was supposed to be on display at the Maritime Museum of the Atlantic.
- Pugwash shares her name with the fishing and salt mining village of Pugwash, Nova Scotia, located on the Northumberland Strait at the mouth of the Pugwash River. The village takes its name from the word "pagwe’ak", a native Mi'kmaq word meaning "deep water".
- ERTL models (retired)