I can’t knock the OS stuff ,Got one in my pack right now, However there are some alternatives, when I'm out on the big walks, Great Glenn Way, West Highland Way ,Some walks require more than one map, not to cheep, But the Harvey, map-guides in polyurethane are the best maps to use by a long shot. Tough, waterproof so no problem to use in the rain, so you don’t need extra Polly bags for protection, and cover the hole walk on one sheet. And they last ages, Available at most outdoor stores.