In Key West, Florida, marlin fishing is a popular tourist activity. Many people come to Key West specifically to fish for marlin, as the waters off the coast are home to many of these large fish. Marlin fishing can be done year-round in Key West, but the best time to catch them is during the summer months. There are many charter companies that offer marlin fishing trips, and they can range from half-day trips to multi-day excursions.