Just choose one of these ways: 1. Using a Broadsword: Using a Broadsword can quickly defeat enemies near you, though, it could easily kill a low-level pirate. 2. Grenades: Another way you could do would be using grenades. I don't recommend this way, though, if you want to, you can. If you're trying to level grenades there, go to General Darkhart. 3. A Blunderbuss: I recommend this, because it easy and quickly can take out ghosts in about one or two hits. 5. Cutlass: If you don't have any of the other stuff, just use a cutlass to defeat them all one by one. Though, it might take a while.