[CollegeRepublican]

Normal waves in the ocean are caused by when wind blows across the water's surface. The wave height is determined by wind speed, fetch, duration, and the water's depth.

Here is a wave machine. Play with it to see how high you can make a wave.
http://www.pbs.org/wnet/savageseas/multimedia/wavemachine.html

[Terabitten]

97 feet was my best effort.