Once in a Lifetime - The Sea Always Wins. 

One in a series of six documentaries about the people and places of West Cornwall. Made in 1982 by Yorkshire TV and directed by Barry Cockcroft.
It features Roland Morris - a well known local diver and 'character' from Penzance. Described as a 20th centurty 'buccaneer', it details his clashes with the National Trust and the 'treasure' ship he located at 'Dollar Cove' on the Lizard Peninsula.
Transferred from a Betamax tape recorded 14/12/82. At the time the recorded quality was the best you could hope for with domestic recording equipment