I've got a feeling that this one may have been a replacement for Robert Newton's Long John Silver. Mr. Newton was the grandest pirate of all, he made Johnny Depp as Captain Jack Sparrow look like Mr. Chips. But he was dying of alcoholism and maybe the BBC needed a new pirate show.
Only 39 episodes were made of The Buccaneer. Robert Shaw went on to bigger and better things. He died tragically just as he was really reaching the heights as a player with great performances in Jaws and in The Sting. What a great loss he was.
Shaw's Dan Tempest was not in the Robert Newton, but rather in the Errol Flynn tradition. He would have made a grand swashbuckling hero if his career hadn't taken other directions.
Like Flynn's Captain Blood, Dan Tempest was a former pirate newly pardoned and working for law and order and his majesty the king, doing a few odd jobs policing the seas. His three top crewman, Gaff, Taffy, and a Spanish renegade named Armando were as salty a bunch as ever shivered any timbers.
He also had a British naval officer, Lieutenant Beamish played by Peter Hammond who worked with Tempest, sort of in tandem. Beamish was squeamish about working with a pirate, but after a while he sort of just went with the flow.
With all the great film parts that Robert Shaw played, it's Dan Tempest that I remember him best for. I do so wish I could see some Buccaneer episodes.