The 35- to 40-minute trip to the Dry Tortugas skims above the trademark windowpane-clear waters of the Florida Keys. The seaplane perspective provides an awesome experience that could result in a stiff neck from craning to look out the window and down from 500 feet above. In the Flats that edge Key West, you can spot stingrays, sea turtles, and sharks in the shallow water. In the area dubbed The Quicksands, water plunges to 30-foot depths and sand undulates in dune-like formations. Shipwrecks also festoon these waters; here's where Mel Fisher harvested treasure from the Atocha and Margarita. His 70-foot work ship, the Arbutus, deteriorated and eventually sank at the northern edge of the treasure sites. With its mast poking out above water, it's easy to spot and fun to photograph. From there, the water deepens from emerald hues to shades of deep blue as depths reach 70 feet. Seaplanes of Key West's most popular trip is the half-day option, where you spend about 2½ hours on Garden Key. The seaplanes leave during your stay, so be prepared to carry all of your possessions with you. The morning trip beats the ferries to the island, so you'll have it to yourself until the others arrive. Snorkeling equipment, soft drinks, and birding lists are supplied.