Mooring Depths, in feet
Dock Location Minimum Water Depth
Beaver Island 2
Belle Isle 13
Birch Island 5
Caribou Island 10
Chippewa Harbor 7
Daisy Farm 9
Duncan Bay 6
Duncan Narrows 6
Grace Island 3
Hay Bay 5
Malone Bay 6
McCargoe Cove 7
Merrit Lane 8
Moskey Basin 8
Rock Harbor 5
Siskiwit Bay 5
Three Mile 9
Todd Harbor 4
Tookers Island 7


  • The marina at Rock Harbor Lodge is open from about mid May through mid September. Diesel fuel, gasoline, and oil are available at Rock Harbor- gasoline and oil only at Windigo.
  • Most park docks accommodate cruisers of moderate draft, but check ahead of time to make sure that current conditions will allow mooring.
  • Holding tank pump-out stations are located at Rock Harbor and Windigo. Discharging human waste into Lake Superior violates the laws of the United States, Canada, and the state of Michigan.
  • As of 1998, visitor entrance fees are: $4 US per individual per day, $50 US per individual per season, $150 US per boat
  • All boaters should carry Lake Survey Chart 14976, "Isle Royale", which may be purchased from the park.
  • Boaters wanting to cross from the mainland to Isle Royale should have an FM radio of sufficient power to reach shore. Channel 16 FM is monitored by Mott Island and Windigo Ranger Stations during the day and constantly by the U.S. Coast Guard.
  • It is recommended that boats less than 6 meters in length do not cross Lake Superior from the Keweenaw Peninsula. Boats up to 6 meters in length may be transported on the Ranger III, or towed behind one of the other passenger ferries serving the island.
  • U.S. citizens returning from Canada, and Canadian visitors to the island must clear U.S Customs. A U.S. Customs and Immigration Officer is usually available during normal working hours at Rock Harbor, Amygdaloid, and Windigo Ranger Stations.
  • Compressors and generators must be turned off between 2200 and 0600 EDT. Noise not only disrupts the solitude of other visitors, it lowers the reproduction rate of the many threatened and endangered wildlife species found on Isle Royale.