Pirates for the day

Slate has an article, Why Do Pirates Talk Like That?, by Gretchen McCulloch, a linguist and the contributing editor of Slate's Lexicon Valley blog:

Break out the Arrrrr, me hearties, because today is International Talk Like A Pirate Day! But where does our idea of pirate speech come from?
Although popular pirate literature dates from the 1700s, starting with A General History of the Robberies and Murders of the Most Notorious Pyrates in 1724 and reaching its heyday around the publication of Treasure Island (1883), pirate speech didn't always sound like it does now.  In The Pirates of Penzance (1879), for example, there is nary an "avast" nor "matey" in earshot. But then, Gilbert and Sullivan's pirates are atypical for other reasons: the opening song, for example, has them drinking sherry, not the now-traditional rum.
The linguist Molly Babel points out that our current associations of pirate speech came about largely through film, and that one of the primary influences was the native West Country dialect of Robert Newton, who played the main characters in several early pirate movies: Treasure Island in 1950, Blackbeard the Pirate in 1952, and Long John Silver in 1954. In a selection of some of Newton's finest piratical moments, you can already hear some of the phrases that would become standard pirate fare, such as "flay your shriveled tongue" and "scurvy dog".
So influential was Newton and his interpretation that a variation of West Country English became standard for subsequent portrayals of pirates on stage and screen. In an interview with the Vancouver Sun, Babel elaborated on the similarities between the two:

Speakers of the West Country regional dialect tend to emphasize their r's, unlike other British regions, said Babel. They tend to replace the verbs 'is' and 'are' with 'be,' and indeed, use the word 'arrr' in place of 'yes.' "If you go to really rural places you'd probably still find people say, 'I'm sitting in me chair', " Babel said, cautioning that, despite the continued usage of these terms, locals probably wouldn't sound all that much like pirates anymore.
Other features, like the use of do to express a repeated or habitual action, are found among older speakers of West Country English but are perhaps too subtle for most imitators of pirate speech.

It's not entirely arbitrary that Newton should have used an exaggeration of his own dialect to play Long John Silver. The West Country (the southwest corner of England, including Cornwall, Somerset, Devon, Dorset, and Bristol) has a long seafaring tradition, and so many historical pirates would likely have spoken in a similar way. Both Blackbeard and Sir Francis Drake were from that area, although Drake was technically a privateer.
Interestingly, the West Country's influence on popular culture isn't just pirate speech. Newfoundland English is ultimately related to that of the founding settlers from the West Country, and it's also the dialect of the incredibly catchy 1976 hit song Combine Harvester. But perhaps the most famous inhabitant of the West Country is Hagrid from the Harry Potter series. Can't you just imagine Hagrid saying: "Yer a pirate, Harry"?

Rico says he almost missed Talk Like A Pirate Day but, arrgh, fortunately didn't...