Blood Tide is a 1982 British horror film directed by Richard Jefferies, and starring James Earl Jones, José Ferrer, Lila Kedrova, Lydia Cornell, Mary Louise Weller, Martin Kove, and Deborah Shelton.

Its plot follows a young American couple visiting a Greek island where the husband's sister disappeared; they soon find that an ancient monster has been released, forcing the villagers to return to the practice of human sacrifice to appease it.

Inside, Frye gets drunk and uses a homemade bomb to unseal a walled-off tunnel which bears a sigil engraved above it.

Neil and Sherry visit the convent in an attempt to locate Madeline, but a nun forces them to leave.

A short time later, a bloodied and shocked Sister Anna, the mother superior, stumbles into the festival.

As Neil helps pull Madeline from the cave, Frye detonates it, blowing up the serpent and sacrificing his own life.

[4] TV Guide offered similar criticism, awarding it 1/5 stars, calling it "An embarrassing picture for all concerned, but fun for devotees of "bad enough to be good" movies.