Nice try Aqua Man. What you have described is what we called vector difference of the true wind and water speed. Check this out:
The problem is, that when the wind is blowing against 3kts current, it produces much bigger waves, then the wind 3kts stronger blowing over the still water.
I asked dr Robert Weller from Physical Oceanography departament, Woods Hole Oceanographic Institution and he suggested Wikipeda article on Rogue Wave:
and this article:
I haven't checked the second one, but from Wikipedia it seems, that current-wind interaction is the cutting edge of physical oceanography and is still not very well understood.
One new idea I got is, that when the wave is produced over still water, it has its length, and then, when it enters opposit current its shortening, what makes it steeper, sometimes up to the point of breaking.
Thanks for interesting discussion.
btw. I've seen Poseidon, the movie. It is about rogue wave incident, but 50m high wave on flat sea is rather unprobable. Movie is OK, but not great. The Guardian with Kevin Costner is much better in my opinion.