NavList:

Frank, the iceberg was a very simple first approximation. We see the results (top part of the wave). John, I think, understood that I wanted him to look "under" the ocean surface.

You said "What we're trying to figure out here is how it actually works. A proper theoretical model, even if it's very simple, can help us figure out the circumstances under which one can get useful navigational information from the appearance of waves in a current."

That's work, and it's not going to come from me. Yuk, ish, eewww. I'd rather clean the gutters. I'll leave the math to, ummm..., the reader. A million dollars to you (and dinner from me) if you can invent the math to solve the Navier-Stokes equations, by the way. It's one of the Millenium Prizes. And you may get a Nobel award as a kicker. For those of us who played Navier-Stokes for a living, it's akin to doing Newtonian physics without calculus. Assume this, assume that. Then, three days later and about five pages into the cross products and curls, notice that you have contradictions. Start over. Get the equations "right" (on which try?) and start the numeric analysis game - which you probably know that you need to guess an answer then build a solution. Then test with real-world data.

To me, in known current areas, useful navigational information is stuff like this:

http://www.srh.noaa.gov/mlb/?n=gulfstream_nomogram

And listening to the voice of experience, of course.

Joe