Which pirate is standing in front of what mark.?
You need to be a bit more specific as there's multiple pirates & at least 2 marks that can be blocked by them.
There's one pirate that blocks the mark where you need to place the stone to get the gold key. He moves after you give Jack the money from the pub.
There's another mark that jack stands in front of on the ship. Once you put all 4 canonballs into the marks, Jack tells you "happy looting;" giving you the chance to tile the barrel of rum to the pirates in the beach. Once you do that, Jack moves from his place on the ship, giving you access to the marker.