User blog comment:J Fan/Dead Men Tell No Tales - Details: Story, Characters and Setting/@comment-25426315-20150430110621

"The vessel is the same ship that fell under attack at the helm of the Flying Dutchman in a dramatic ambush scene in the second film but was deleted from the final cut and had not been seen since."

Spanish soldiers that the Flying Dutchman has probably sent to the Devil's Triangle, and that's why they want to vanish EVERY pirate at sea. And they look like ghosts, pretty much. Look at the make up and clothes.