The Great American Diving Company, St. Peters

At The Great American Diving Company, swimmers and scuba enthusiasts plunge into a 10-foot-deep, custom-built training pool heated to a balmy 85 degrees. Under the guidance of PADI-certified instructors, students in Open Water Diver classes learn to breathe and explore beneath the surface, opening the doors to continue underwater education and obtain certification or finally put to rest a fear of really big puddles. Divers can gear up for their next expedition in the shop, and the staff also leads scuba trips to diving locales.