Miami Harbor is a major saltwater harbor within the broader expanse of Biscayne Bay, characterized by deep dredged channels and a working port. The primary paddling experience here involves navigating the sheltered but active waters of the bay, with routes often connecting to nearby islands. A key launch point is Oleta River State Park, which offers a protected mangrove trail that spills out near Sandspur Island and is considered a safe starting location suitable for beginners. Another launch option is Haulover Marina, but this is recommended only for advanced paddlers due to its exposure to open water and the requirement to cross the main Intracoastal Waterway channel. Paddlers must yield to all motorized vessels in this waterway and strictly stay out of the marked shipping lanes in the harbor itself.

Tidal currents are a dominant and critical safety factor. The water moves fast through the cuts and channels, particularly near Bakers Haulover Inlet, where currents can be strong. Paddling against a strong tidal flow is a losing battle. For trips toward islands like Raccoon Island, planning around the tide is essential; paddlers should aim to hit the water at the beginning of an incoming tide to get a free ride toward the island, as a falling tide pulling water out to the Atlantic can make the return trip exhausting. Wind is another major consideration, as afternoon sea breezes over 15 knots can create harsh chop on the open bay. The crossing of Miami Harbor itself requires particular caution due to larger ships entering and leaving the port.

The environment is a mix of concrete seawalls, ancient mangrove roots, shallow seagrass beds, and deep channels. Notable sights from the water include the Miami skyline, the Port of Miami, and residential islands like Star Island with waterfront mansions. The area is home to vibrant marine life, including dolphins and sea turtles. For rentals, the BG Oleta River Outdoor Center inside Oleta River State Park offers single and tandem kayaks, though rentals can be in high demand on weekends.