The Marquesas Keys Reef Line is a great treasure of a diving site. The keys are in the shape of a circle, a geographic structure called an atoll that is usually formed by volcanic activity but at the Marquesas was caused by a meteor. The keys are located about 30 miles west of Key West. The keys provide a gorgeous beach and mangrove setting and some of diving in the Gulf, in part thanks to the preservation efforts in this area. The Marquesas keys are surrounded by an abundant coral reef gardens. The Marquesas are considered one of the best diving sites around Key West as far as the abundance of sea life that is found here. Some of the most common species you will find down here include snapper and grouper.