name='schalcken']Saw this one as a kid, and frightened me to death.
Something to do with couples on a barge/canal holiday and they pick up a stranger who is having trouble with his canal boat (Dead Calm-esque) and he turns psycho and attacks them with a can opener.
Any ideas what this might be please?
Could be Way Upstream (1987).
More at the IMDB:
Way Upstream (1987) (TV)
Euryale.