True
It was Robert Newton in the 1950 Disney version.

Actual 17th Century pirates were often from rural areas of Britain, often in the West Country. Edward Teach aka Blackbeard was thought to be from Bristol.

BUT, not all West Country accents sound exactly the same. Newton's Dorset accent has, over time, become corrupted into some generic Southern-English-West-of-Reading pisstake.
( shinyshinyscalp less a man, more a way of life, Fri 1 Jun 2012, 15:23, Reply)