There are a total of 17 guide book pages in Dead Island Riptide. Finding all of them will earn you the “Professional Tourist” trophy / achievement and they are also a requirement for other collectible related trophies and achievements. In the inventory (press select) you can see which collectibles you have already found. They are all numbered, so you can identify missing collectibles easily. This video guide shows them in order of accessibility, but the time line below provides a detailed overview. After finding a collectible it will be saved automatically. You can still access all areas, side quests and collectibles until you use the boat in chapter 13.