All right I got it...

First go buy "Learning Maya 7, Maya Unlimited Features." It has a great ocean creation walk through. Then I sat down and tried to make a tidal wave for ya...this is what I came up with.

The Ocean was done under the Fluid Effects>Create Ocean, and then the settings were just adjust for wave height, frequency, wind speeds, foam, color, etc.

I am sure you can work with a bunch of the settings, because there are a million of them, to make it just what you want. I did all this in like 20 minutes, so if you really take the time I am sure you can get it to look real nice. I didnt try to animate it but I am sure you can just set the ocean to be normal (attachment 1) and then set a time point to make the wave (attachment 2)...

Enjoy.