On 16 April 1951, the HMS Affray, one of Britain's latest A-class submarines, sailed from its base in Portsmouth. On board were 75 submariners bound for a top-secret training exercise. They were never seen again. In the first of two programmes, Edward Marriott investigates what really happened in the Royal Navy's worst disaster since the Second World War.
In the second of two programmes, Edward Marriott pieces together what happened to submarine HMS Affray, lost under mysterious circumstances after sailing from Portsmouth in April 1951 on a top-secret training exercise. Seventy-five crewmen were lost in the Royal Navy's worst disaster since the Second World War.