The Shark Valley tram is a two-hour, ranger-narrated, open-sided ride around the full 15-mile loop with a stop at the observation tower. It is the highest-value thing in the Everglades for anyone who does not want to cycle in the heat. Reservations are required from December through March and it sells out; book before you drive out.
Bikes on the same loop give you the road at your own pace, and the alligators lie on the verge of it. There is no shade for most of the circuit and 15 miles in August heat is a serious undertaking. Rentals are available at the entrance.
The Anhinga Trail at Royal Palm, eight miles inside the Coe entrance, is a half-mile boardwalk over a slough and the most concentrated wildlife viewing in the park: alligators below the rail, anhingas drying their wings, herons, cormorants, softshell turtles, sometimes otters. It costs nothing beyond the entrance fee and takes 45 minutes.
Airboats are covered in full on our airboat tours page. Short version: loud, fast, fun, and mostly not in the national park.
Backcountry and Florida Bay boat trips leave from Flamingo and from the Gulf Coast visitor centre at Everglades City, and they take you into mangrove tunnels and island chains you cannot reach any other way. This is where crocodiles, roseate spoonbills and manatees are most likely.
Ranger-led slough slogs are the best thing the Park Service runs here: you walk into the water in old shoes, waist deep through a cypress dome, and it changes how the place reads. Seasonal, limited, and worth arranging your day around.
Kayaking at Nine Mile Pond, Hells Bay and the Gulf Coast gives you the quiet version. Book a guide unless you can navigate mangroves competently; the trails are marked with numbered poles and people do get lost.