It's a very cool dive. There are alot of trails there the more you dive there the more advanced they become. They have one that is on the right side of the main dock you enter at 80ft and swim up to 60ft and theres air trapped, you can take off your mask and talk. Then hold your depth guage up in the air while it reads 60ft.
I was lucky enough to have a friend that trained for West End Diving I took my PADI AOW and my deep from him and we dove all over the mine. It was cool standing on the bottom under the dock and looking straight up and seeing people on the dock over a 100ft above you.
West End Diving runs Bonne Terre Mine. In fact it is the oldest dive shop in St. Louis still going strong. The owner Doug was one of the pioneers that introduce diving to St. Louis. There were a handfull that opened a shop then after awhile they all split up. West End Diving, The Diving Chamber, Inner World, The Dive Shop, Bi-State Underwater and Underwater Sports came from the origional group. West End is the only one left of the old shops.