Boatnerd Discussion Forum

Take a trip over the rock cut if you can. Great spot for watching Boats.

Just to add to the great explanation Dave posted, the gates he speaks of are not the gates of the locks themselves but a line of water control gates that span the St. Mary's River between the American locks and Canadian lock. Enjoy your stay there!

Usually when vessels enter the St. Marys River system, either at Whitefish Point downbound, or DeTour upbound, they vessel will receive the flow rate in the river expressed in cubic feet per second. This is controlled by the gates at the Soo and lets the captain know what kind of current to expect. He will also be told the water level in the upper river and the Rock Cut.
The Rock Cut is a narrow passage on the west side of Neebish Island that has been cut out of solid rock. The water level in the Rock Cut is very important to loaded vessels because they may hit bottom if they are loaded deeper than the available water depth. The level of the bottom of the Rock Cut is similar to the depth of the water over the gate sills at the locks. There are times when the water level drops at the Soo such that downbound loaded vessels may go to anchor in Whitefish Bay. This is usually caused by an East wind that blows Lake Superior over to Duluth and lowers the upper St. Marys River. On the other extreme, a north wind can shift Lake Huron to the south and lower the water level below the locks which is where the Rock Cut is located. Water depth is a very important consideration for any vessel traveling the St. Marys River.

This is probably a silly question but I thought I'd ask anyway! I'm staying on the shores of Whitefish Bay for the next 3 weeks and have been listening to the broadcasts from the Soo. It's been soooo cool to hear the Captains go thru the Locks after seeing the freighters pass by or anxiously await their upbound passage. Is there a site or place on boatnerd.com that might explain some of the things I'm hearing....like the flow of the water 'on the approach' and what the 'rock passage' is and all that? I realize that's what the Captains are trained/educated about and hats off to you guys....you're awesome!