I recently dove in Bonne Terre, MO and their policy is that before making any dive beyond trail 3, you must complete trails 1-3 in order.
After you dive trails 1-3, they stamp 3 pages of your log book, and if you return to Bonne Terre to do dives beyond trail 3, you need to show those stamps. I don't know if there are other operators that work like this, but I guess it is another reason for a log book.
After you dive trails 1-3, they stamp 3 pages of your log book, and if you return to Bonne Terre to do dives beyond trail 3, you need to show those stamps. I don't know if there are other operators that work like this, but I guess it is another reason for a log book.