Scuba Unlimited, Cincinnati

Back in 1974, the first student of Scuba Unlimited splashed into the water decked out in scuba gear. Since then, the instructors have educated countless pupils and fueled a desire to explore the unknown with the help of goggles, fins, and air tanks, which are available for lessons and rentals. More than 30 teachers and divemasters lead courses for a range of experience levels, from beginners to advanced open-water divers who inconveniently fell in love with mermaids.