The Northwest Channel is the deepwater gap between Key West and the shallow flats and islets beginning two miles to the west. The main channel is 5 miles from Key West and angles north to south from the Gulf to the Atlantic. It is large and deep and is used by commercial and fishing vessels, particularly when traveling towards the southwest mainland coast of Florida.
The channel features several wrecks and numerous ledges, as well as jetties, all of which are home to many species of fish year-round. From the east, the Northwest Channel is the first deep passage in 45 miles that fish can use to migrate from the Atlantic into the Gulf. The Flats on either side of the channel are excellent Tarpon and Permit fishing grounds, and the deeper holes hold large schools of Tarpon in the spring.