Here are the locations of the eight pirates. Two of them run into the nearby buildings, so make sure to check inside those buildings.
1) Above the SE corner, above the river.
2) In the SE corner, and goes inside the house when you approach.
3) In the SW corner, on the wharf to the left of a crane.
4) West side, just below the pirate ship, above the fishing poles.
5) West side, just above the pirate ship, across from the Iron Maiden.
6) West side, below building to the left of the Iron Maiden. To the left of the starfish.
7) In front of the Optician's building.
8) To the left of the Optician's building. Runs into the building when you approach.