The crew of a deep-sea trawler face a series of life-threatening challenges on the open ocean. While the ship battles brutal weather and treacherous icy conditions (the metaphorical "black ice" of the sea), the plot centers on the internal and external conflicts of the sailors.

Gordon Jackson
Hamish

Ronald Fraser
Tom

Paul Carpenter
Greenslade

Ewen Solon
Capt. John Dodds

Edwin Richfield
White

David Oxley
Matt

George Tovey
Simpkins
Ben Williams
Bert Harris
Claude Kingston
Johnny Dodds
Barry Keegan
Mick