Where to Watch High Tide (1980)

Ian McShane stars as Peter Curtis, who has just been released from prison after serving four years for manslaughter. His victim's mysterious last words lead him on a frantic quest for answers in the tidal estuaries of the West of England, where he finds himself on a collision course with other parties who are as eager to solve the mystery as he is, and are seemingly even prepared to kill to find the answer.