Doctor Who - Legend Of The Sea Devils, had an official 7-day rating of 3.47 million viewers.
The figure includes all those who watched the episode within 1 week of transmission. The figure is a substantial increase over the initial overnight figure and was enough to make Doctor Who the highest-rated programme on BBC Television for the day.
Overall Doctor Who was the third most-watched programme on British Television for the day, with ITV's drama The Thief, His Wife and the Canoe taking top place.
Doctor Who was the 24th most-watched programme for the week.
The rise from the overnight figure was enough to prevent The Legend of the Sea Devils becoming the lowest-rated episode in Doctor Who history. That accolade is still held by episode one of the 1989 story Battlefield with 3.1 million watching. It does however mean that the Sea Devil episode is the lowest-rated story since the series returned in 2005.
Doctor Who will return for one more story in 2022, a climactic regeneration story shown to mark the BBC's 100th birthday, before a new production team, headed up by Russell T Davies, takes over for series 14.