here's a link to a bathymetry link for lake ontario.
http://www.ngdc.noaa.gov/mgg/image/ontario1280.jpg
Lake Ontario, although slightly smaller in area, is much deeper than its upstream neighbor, Lake Erie, with an average depth of 86 meters (283 feet) and a retention time of about 6 years. Major urban industrial centers, such as Hamilton and Toronto, are located on its shore. The U.S. shore is less urbanized and is not intensively farmed, except for a narrow band along the lake.
Lake Ontario is one of the five Great Lakes of North America. The lake is bounded on the north by the Canadian province of Ontario and on the south by Ontario's Niagara Peninsula and by the U.S. state of New York. It is the smallest of the Great Lakes and the only one that does not border with Michigan.