Hussey Sound is a tidal passage within Maine's Casco Bay, located between Long Island and Peaks Island. It serves as a significant crossing point for paddlers heading to the outer islands, such as Jewell Island, and is a feature in common routes like circumnavigations of Peaks Island. The sound is exposed and can become lively, with conditions influenced by wind against tide, particularly at its entrance where easterly swells meet an incoming tide. The tidal current is a primary factor for planning, with published data for Cow Island showing flood currents exceeding 1 knot and ebb currents slightly weaker, with slack water periods occurring. Paddlers should time crossings to coincide with favorable currents and calm conditions.

The area is characterized by open water with significant fetch, making it susceptible to wind and wave action. Exposed crossings of Hussey Sound can be unenjoyable or challenging in strong southerly winds. The sound sees boat traffic, including the Casco Bay Lines ferry, the Wabanaki, which operates near Great Diamond Island. There are no dedicated paddler launches directly on Hussey Sound itself. Common put-in points for accessing the sound are East End Beach in Portland and the boat ramp at Falmouth Foreside, both requiring a paddle of several miles through other island passages to reach Hussey Sound.

The surrounding environment includes numerous Maine Island Trail Association (MITA) islands, such as Little Chebeague, Jewell, and Cow Island, which offer camping and day-use opportunities. The coastline features ledges, small islands like Pumpkin Knob, and the cliffs of Peaks Island. Wildlife sightings include seals and seabirds. The overall experience is one of a coastal thoroughfare that connects the more protected inner bay with the exposed outer islands, requiring careful assessment of tide, current, and wind forecasts for a safe passage.