Click here for the Wrecks Gallery! On any given weekend, hundreds of boats fill Fort Lauderdale's waterways and ocean to take full advantage of the many varied outdoor activities available in the ''Venice of America.'' Although many make the trek for the topside attractions, it is below the ocean's surface that divers truly appreciate what the greater Fort Lauderdale area has to offer. The three distinct reef bands off Fort Lauderdale's shores are part of the South Florida reef system that starts in the Dry Tortugas and runs parallel to shore for over 250 miles to north of the Jupiter Inlet. Currents tend to be mild on the shallow reefs, but can get strong on the deeper sites. Along the second reef line, a series of reefs ideal for divers of all experience levels lie north of Port Everglades Cut. These dives begin as you drift north through a wall of fish to Opal Towers, a 12-foot vertical ledge found in 40-45 feet of water. Just beyond the highest point, the reef line takes an abrupt turn to the east before resuming a south-north direction. A large school of spadefish uses this nook as a break from the mild but ever-present current. The height of the ledge gradually shrinks as the reef continues north. After a short break in the reef, the Hillsboro Ledge comes into view. Small overhangs and caves in this 5- to 7-foot-high ledge are loaded with invertebrates, including both Spanish and Florida lobsters. The two large green moray eels that share the north end of the reef are accustomed to divers and sometimes leave the safe confines of their holes to investigate the bubble-blowing aliens. The Hillsboro Ledge then makes an abrupt turn to the east. At this point, swimming north about 100 feet takes you to the beginning of Separated Rocks, where a resident barracuda extends a toothy welcome to the site. He'll often follow divers around for the entire dive. As the name implies, the reef is actually several coral islands separated by sand. Pay attention to your direction, especially on lower visibility days or you'll spend half your dive looking at sand. The Pompano Drop-Off is an east-facing ledge that starts at 15 feet and drops abruptly to 30. Between two of the mooring buoys lies The Nursery, an amazing interactive nurse shark encounter designed to accommodate both divers and snorkelers. Righteous Wrecks Along the same reef line just a few buoys south lies the wreck of the Copenhagen, Broward County's first underwater achaeological preserve. The vessel crashed into the Pompano Drop-off in 1900 during a storm. Until World War II, much of the wreckage was still above water. It was first used as a target practice, then blown apart to prevent German U-boats from hiding behind it. Although the hull collapsed years ago, there is still a ton of marine life surrounding the site. The latest addition to the wreck collection off Fort Lauderdale is the 150-foot coastal freighter United Caribbean. This vessel received national attention in 1993 when it ran aground on a sand bar 200 yards off the New York shoreline with 228 illegal Chinese immigrants aboard. A line of stones a couple hundred feet in length link this new addition to one of the area's most famous dive sites, the Sea Emperor. When the 170-foot hopper barge sank, it flipped over, spilling tons of old concrete piping just east of the wreck. The piping began accumulating growth almost instantly, which led to the arrival of larger predatory species. Just east of this pile of rubble, South Florida Diving Headquarters started feeding the rays and eels several years ago to create the ''Aqua Zoo.'' Today, several charter operators take more than 300 divers weekly to experience an incredible interactive dive with as many as five Jewfish, and a dozen southern stingrays as the main attractions. Two green moray eels and a five-foot nurse shark are also regulars at the Aqua Zoo. Scuttled as a joint venture between Broward and Dade counties, the five oil-drilling platforms known as Tenneco Towers were sunk about a mile and a half offshore on the county line. Only three of these structures are within recreational diving limits. The ever-present current passes through these open structures, producing some of the healthiest and most mature growth found on any site of similar age. Most charter operators will take you to the largest tower, which rises to within 60 feet of the surface. The wreck of the Mercedes I received national attention in November 1984 when a Thanksgiving storm caused her to crash into the seawall one door down from the Kennedy estate in Palm Beach. It took four months and almost $250,000 to finally remove the ship. The wreck now sits upright in about 85 feet almost due east of Sunrise Boulevard. The stern and wheelhouse, now listing hard to starboard, are still barely attached to the hull. An observant diver will find a motorcycle still sitting on the main deck placed by a prankster years ago. The combination of a coral garden about 100 feet due east, the ledge running north adjacent to the wreck, and the wreck itself make the Mercedes a haven for fish life. Whether your pleasure is exploring the belly of an old freighter, petting a stingray or nurse shark, or looking for small invertebrates in the openings of a sunken oil platform, the Fort Lauderdale area offers a multitude of amazing dive sites. For more information about Fort Lauderdale diving and Fort Lauderdale vacation activities, click onto the Greater Fort Lauderdale Visitors Bureau home page below.