Here's why:
* Location Filming: The show uses the real village of Port Isaac as its setting.
* Local Casting: It's common practice for productions to use local residents as extras, especially in shows that heavily feature a specific location.
* Community Involvement: Port Isaac is a small village, and local residents often get involved in filming activities. This would be a natural way to cast extras.
However, it's important to note that:
* Some extras might come from elsewhere: While many extras would be from the village, the production may also have cast some extras from nearby towns.
* Exact details not publicly available: The production hasn't publicly confirmed the specific origin of all extras.
Overall, it's safe to assume that a significant portion of the extras in Doc Martin were indeed from Port Isaac.