UFO - Destruction

UFO is a 1970 British science fiction television series about the ongoing covert efforts of a government defense organization to prevent an alien invasion of Earth. It was created by Gerry Anderson and Sylvia Anderson.

A single series of 26 episodes (including the pilot) was filmed over the course of more than a year; a five-month production break. Production then moved in Buckinghamshire. UFO was first broadcast in the UK and Canada in 1970, and in US syndication over the next two years.

The Andersons' live-action science fiction movie Doppelgänger (also known as Journey to the Far Side of the Sun) is considered an immediate precursor to UFO, which was their first entirely live-action TV series (their previous shows had used marionettes). The series featured actors, costumes, props, locations and music that had appeared in the film, and 11 cast members of the film appeared in at least one episode of UFO.
"Destruction"
The aliens attack a Royal Navy destroyer that is dumping sealed containers of highly toxic nerve gas in the sea.