These maps were not what I thought they were when I first bought them (GM aid), but they turned out to be so much more! As previous reviewers have noticed, there is close to no plot-revealing details on the map, which makes them great player aid for your campaign.
You just have the players find a copy of the location's map in-game (Captain's cabin, by example), and then hand them the IRL massive copy of it. My players liked it so much they used color-coded stickers with handwritten pictograms on them to mark their progress and exploration of the different locations. The map made the sandbox parts of the game way more interesting and immersive.
I would recommend this product to anyone who wants to run at least 2 modules of the Serpent's skull campaign.
