Seiche Effect on Great Lakes

[Ed Haley]

I read Larry DeMers post on the Seiche effect on Lake Superior and it brought back some memories while I was anchored inside a small pocket of Main Duck on the east end of Lake Ontario. I had about 2 feet of water under my keel. The wave trough of the seiche must have been over 2 feet because late at night Jasmine was on the bottom and heeling over slightly. I woke up with a massive injection of adrenaline and looked out to see other boats with non-perpendicular masts. Then we were afloat again and then on the bottom, I'd guess at 15 minute intervals. High frequency tides on the Great Lakes. No tide prediction data here!! Seiche happens!



eghaley@twcny.rr.com

[Larry DeMers]

Hi Ed,

You bet "Seiche Happens!" hehe.. it was an amazing thing to us..never thought we would have to deal with currents..but I find it an interesting facet of this hobby..just when you thought you had a pretty good grasp of docking..seiche tides ranging up to 3ft. are thrown into the picture.

The wave front is traveling at an incredible 7-800 mph underwater..in the Great Lakes or the Ocean (as in Tsunami's). Basicly it's the bowl of water sloshing back and forth effect.

Hope all is well and you have a great summer!

Cheers!

Larry

I read Larry DeMers post on the Seiche effect on Lake Superior and it brought back some memories while I was anchored inside a small pocket of Main Duck on the east end of Lake Ontario. I had about 2 feet of water under my keel. The wave trough of the seiche must have been over 2 feet because late at night Jasmine was on the bottom and heeling over slightly. I woke up with a massive injection of adrenaline and looked out to see other boats with non-perpendicular masts. Then we were afloat again and then on the bottom, I'd guess at 15 minute intervals. High frequency tides on the Great Lakes. No tide prediction data here!! Seiche happens!

demers@sgi.com