Trivia: Sylvester McCoy was given a new costume for Season 26, with a darker jacket, hatband, tie and handkerchief to reflect the gradual development of the Seventh Doctor's personality, and to show that the Doctor himself was getting 'darker' and more serious. To surprise viewers with the revised outfit, it was decided the Doctor would begin the season wearing a duffel coat over his regular clothes, the belief at this time being that "The Curse of Fenric" would be the 'lead story' for season 26. Later however, it was pushed back to third in transmission order, meaning that the effect went for nought, as the costume had already been seen in the first two serials.
Trivia: Watch closely the scene where the Haemovores come out of the sea en masse, and pay particular attention to the two 'child' Haemovores at the back of the group. Those two were Sam and Joe Kent-Smith, who are Sylvester McCoy's sons. They'd come down to the location filming to watch their father working, and found themselves 'roped in' to the filming to boost the numbers of Haemovore monsters.
Trivia: Doctor Who never really recovered from being taken off the air for 18 months in 1985-86. This is borne out by the audience viewing figures, which were consistently the lowest ever for any season of Doctor Who. The average audience figure for season 26 was 4.19 million, with Part 1 of the story "Battlefield" getting the lowest ever audience for a Doctor Who story: just 3.1 million. The last episode of Season 26 ("Survival", broadcast on 6th December 1989), which was also the show's last story (at the time, that is), got an audience of 4.8 million... probably boosted slightly by fans of the show hearing that it was "the last one" - until the new series, that is.