There is a story in the Boston Globe about mysterious waves striking Boothbay harbour, Maine. At low tide the waves swept in and raised the water levels 12 feet, causing some damage in the harbour. They are mysterious because there was no record of seismic activity on the seabed and no offshore storm to account for them. A similar thing happened at Daytona Beach in Florida about 15 years ago and several people were injured and cars were damaged.
The story says that there have been unexplained rogue waves occurring in the Great Lakes. I can confirm that.
A few years ago, I was sailing out of Toronto harbour, south of the islands, in a 27-foot Catalina sailboat, at about 6:30 p.m. on a fine summer evening, during the middle of the week. I was the only boat in sight. The water was quite calm with only a steady ripple of wind disturbing its surface. I was dawdling along at about 3knots, admiring the clouds, when I happened to turn my gaze to the southwest towards Hamilton, 25 miles distant.
I immediately sat bolt upright. Bearing down on my beam, not more than 5 boat-lengths away, were three very large waves. They were not the 12 to 20 feet kind that hit Boothbay and Daytona, but they were large enough to throw my boat on its beam ends and probably throw me out of the cockpit into the water had they hit me broadside, undetected.
I immediately, turned my boat into them, and no sooner had I done so, than the first wave lifted my bow, and then, passing the boat, dropped it into the second wave. That one swept over the bow, up the deck, over my cabin top, into my open cabin, and swamped my cockpit. Then I was dropped into the third wave with the same result.
After I had attended to boat chores to clean up the mess, I scanned the horizon with my binoculars to see what might have caused these waves. It was clear of any large vessels. In fact, it was clear of any boat traffic.
I suppose it is possible that a lake freighter, heavily laden and moving at high speed, crossing from Hamilton to Port Weller, to access the Welland Canal to get to Lake Erie, might have been responsible, but since there was hardly any wind over all of western Lake Ontario, it is hard to imagine these waves could have sustained the energy to travel that distance to my boat.