The Atlantic Intracoastal Waterway stretches 1,200 miles from Norfolk to Miami, but few stretches rival the Grand Strand's salt marshes and tidal creeks for bottlenose dolphin density. Marine biologists attribute the concentration to the collision of warm Gulf Stream eddies and cooler estuarine outflow between Murrells Inlet and Little River, creating nutrient-rich corridors where Atlantic menhaden school in dense clouds. Dolphins hunt these shoals at dusk, their dorsal fins cutting through water turned amber by sinking light. Evening departures from North Myrtle Beach date to the 1970s, when shrimpers began offering deck space to tourists between trawls. The first purpose-built excursion vessel, a 75-foot paddlewheel christened in 1989, mimicked Mississippi River steamers but drew only 18 inches of draft to navigate the Waterway's shifting sandbars. Modern operators run twin-hull speedboats capable of 30 knots alongside replica sternwheelers, each optimized for different aspects of the sunset cruise North Myrtle Beach experience. Speedboats chase dolphin pods into open water; paddlewheels hug the marsh edge where herons roost and cordgrass glows bronze. The waterway itself is a Depression-era public works project, dredged to 12-foot depth in 1936 to bypass the treacherous shoals off Cape Fear. Today its channel markers guide recreational traffic past Vereen Memorial Gardens and the Cherry Grove salt flats, ecosystems protected under South Carolina's Critical Area designation since 1977. Sunset timing shifts 90 minutes between June solstice and December, but golden hour—the 60 minutes before the sun contacts the horizon—remains the target window. Photographers favor the diffused light that renders water glassy and silhouettes maritime forest canopies. Biologists note that dolphins surface-feed most actively in the thermal layer stratification that occurs as air temperature drops below water temperature, a phenomenon visible on infrared scans as a red-yellow boundary. Operators schedule departures to position vessels at optimal vantage points 20 minutes before official sunset. The calculus involves current speed, tide stage, and recent dolphin-sighting logs transmitted via VHF radio. A flood tide pushes Atlantic baitfish into the creeks; dolphins follow. Ebb tide concentrates fish at creek mouths; dolphins wait. This predictability makes sunset cruise North Myrtle Beach tours one of the coast's most reliable wildlife encounters, with sighting rates exceeding 85 percent during May through October feeding season.