Blackwater Sound is a coastal sound on the bay side of Key Largo, Florida, connecting to Florida Bay. It is characterized by a shoreline almost completely encircled by dense, impenetrable mangroves, making navigation to open water challenging without precise knowledge of the few narrow channels. The primary and most noted access point for paddlers is Florida Bay Outfitters, located near mile marker 104.5, which offers a dedicated launch, kayak and paddleboard rentals, and a well-stocked retail shop. Parking is limited, and paddlers are cautioned not to park in the adjacent Caribbean Club lot. The sound can become rough with northeasterly winds, generating significant fetch that can produce waves of three to six feet, particularly with easterly or southeasterly winds. Paddlers must exercise caution when crossing the Intracoastal Waterway channel within Dusenbury Creek, which carries motorboat traffic. A key route for exploration involves paddling from the outfitter along the shore into Dusenbury Creek and its serene mangrove tunnels. Another common trip is to loop through "The Boggies," another narrow channel leading to Florida Bay and the Nest Keys, though finding these passages requires careful navigation as they are easily disguised by the mangrove foliage. The area provides opportunities to see wildlife such as osprey, rays, manatees, dolphins, and the American crocodile in nearby Joe Bay. The surrounding waters are a mix of open sound and tight mangrove creeks, offering a transition from exposed paddling to sheltered, intimate passages. Water temperatures follow typical subtropical patterns, being warmest in summer and mild in winter. The sound is used as a thoroughfare for longer trips into Florida Bay and towards Everglades National Park.