When we were leaving Niagara Falls we decided to make a quick stop at a look-out point overlooking the Whirlpool on the Niagara River. We were still on the Canadian side and looking across to the US. We arrived at a time that a cable car was giving passengers a birds-eye view of the whirlpool. No we didn't take the ride but it will be on our list of things to do when we go next time. Truthfully we did not know of its existence but it is only about five miles down from Niagara Falls.
The cable car got very close but did not dock. It stopped for a little while and then made its way back to the US side. No problems with getting through customs. I think there is also a cable car on the Canadian side as you can see the two sets of cables.
From a page on line found here I learned that the whirlpool is about 120 feet deep and 1000 feet across. It circulates counterclockwise creating one of the largest natural whirlpools in the world. The rotation is caused by the Niagara River taking a right turn, causing the water to rotate.
It is also a great place for salmon fishing because fishermen can often be seen fishing at the whirlpool's edge. Salmon spawn yearly up the Niagara River, passing through the whirlpool on their way to their spawning grounds. The Whirpool serves as a rest area for the Salmon. All I can say is you've got to know what you're doing and you've got to love your fishing!
This page here gives you more information on the Whirlpool Aero Car. It was designed by a Spanish engineer, Leonardo Torres Quevedo and has been operating since 1916.
More information on the whirlpool here and just for a matter of interesting there is a great page on geological information on Niagara Falls here.....
and great information about the Niagara River here.