main duck island

Main Duck Is., ON

Lat: 43° 55.564   Long: 076° 36.788

Quick Reference:

  • Port Type: Refuge
  • Monitors VHF: n/a
  • Charts: CHS 2064
  • Customs: No
  • Coast Guard
  • Transient Docking
  • Anchorage
  • Diesel
  • Gasoline
  • Potable Water
  • Pump Out
  • Washrooms
  • Showers
  • Laundry
  • Repair Services
  • Provisions
  • Pharmacy
  • Hospital/Clinic
  • Banks/ATM
  • Restaurants/Pubs
  • Shopping
  • Internet
  • Amenities
  Important Numbers

Area Coden/a
Police(888) 310-1122


Harbor Distance (nm) Harbor Distance (nm)
Kingston, ON 22 N Cape Vincent, NY 19 NE
Picton, ON 34 NW Sacket's Harbor, NY 23 E
Cobourg, ON 78 W Oswego, NY 31 S


Main Duck Island lies at the eastern end of Lake Ontario, just inside the Canadian border. It is uninhabited. Native peoples used it as a summer camp for thousands of years. European settlers from the Canadian mainland established a small community in the early 1800's and a fishing settlement remained until WW2.

During America's Prohibition, Main Duck Island was a favoured stop-over for rum-runners, waiting for nightfall before making their dash through American waters to bring their illicit cargo to a thirsty public. Some nights there could be a half-dozen ships riding at anchor waiting to depart with their liquid gold. Men like 'Doc' Welbanks, Ben Kerr and Bruce Lowery were among the colourful characters who shot it out with U.S. Coast Guard and O.P.P. on their high-speed dashes across a moonless lake. In the 1950's, the island was sold to John Foster Dulles, the U.S. Secretary of State during Dwight Eisenhower's administration.

The island was purchased from his heirs years later by the Nature Conservancy of Canada and transferred to the Government of Canada. It is now part of the Thousand Islands National Park and an important protected nature preserve.

Save for an abandoned wharf, there are no facilities or services on Main Duck island for transient sailors.


The protected harbour on Main Duck Island lies on the northeast side of the island. There are significant shoals on the south and southwest side of the island. It is estimated that 2/3 of all shipwrecks on Lake Ontario lie off Main Duck Island.

There is a deep, well-protected cove on the northeast side of the island. The entrance channel is marked with a RED buoy (MS2) and a GREEN buoy (MS1). There is a range set up on a course of 232°T. The rear range has a F WHITE light, visible 6.2 NM. The front range has an ISO WHITE light, visible 5.5 nm.

From the North
The approaches are clear to Schoolhouse Bay.

From the South
The harbour lies on the northeast side of Main Duck Island. Coming around the island, be cautious of the reefs that extend out from the southwest side of the island. There is a lighthouse on the western tip of Main Duck Island showing a Fl WHITE light, visible 10.25 nm. About 1.75 nm further off, is a Fl GREEN (M9). If you pass between them but depth range from 33-8 ft / 10-2.5 m so care is needed.

At the easterly end of the island, there is a Fl RED marker (MM2) about .75 nm off the end of the island. Prudent mariners will round the end of the island, leaving this buoy on their port. Continue northeasterly until you clear Yorkshire Island. Once clear, alter course to the northwest until you cross the range leading in to Long Point Harbour. The range lies on a course of 232°T.


Schoolhouse Bay is a a deep, well-protected cove. The only facility there is a public wharf but the water is fairly skinny. There is also anchorage available but it can get crowded. There are no facilities here.








Main Duck Island is part of the Thousand Islands National Park. Going ashore, there is a path that you can take out to the lighthouse. The walking is easy considering the flat nature of the terrain through the fields and woods. There are abandoned buildings from summer residents who lived here decades ago. This is truly a place to leave crowded civilization behind - probably one of the only such places on Lake Ontario.

This Main Duck Island page can give you more information about this unique harbour.

Return from Main Duck Island to Lake Ontario

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