I'm thinking that such a thing apparently doesn't exist, but just thought I'd throw the question out.

I like to kayak, but of course can't be in the water all the time, so I was looking into rowing machines that would let me practice at home. So far, the Water Rower is the most interesting product, since it actually uses water resistance.

But all of the rowing machines I've seen do the same movement -- pulling straight back with both arms. That's not the way I row in a kayak. I have a double-sided oar, and I alternate left and right strokes in a tight rotating movement (you know what I'm talking about). I haven't seen any rowing machine that simulates that motion. Have you seen anything like that?