I took a cruise the first week of June up the Inside Passage in Alaska. Highly recommended! They had this glossy laminated poster on the wall on the ship.
One of the things they did on our cruise was to mark our progress on the glossy laminated poster of the area. It was really nice to see where we had been and would be going. They marked on the map with a wet erase marker, and when we were done, they wiped it off and started marking for the next cruise.
We like wet erase markers on glossy laminated posters for this kind of work. Wet erase markers erase completely and easily. You can also use dry erase markers, but we like the performance of wet erase better.