Actually pirate talk is 18th century seafaring English, or Hollywoods version of it. Here is the Real McCoy in this song about a privateer in the late 1700s.
Barrett’s Privateers
https://www.youtube.com/watch?v=4E45ee-1gMs
Too bad it doesn’t actually state English; can you link a reference?
Still sounds Irish to me.
We have others stating Cornish (never heard of that, so must be very isolated) based on a movie.