I'm going to guess that that is Johann Sauer (sorry if spelled wrong). That Type XXI looks bigger than the one I remember from the R.I. regattas.
It's pretty cool when you see Johann show up with his boats strapped to the top of his car. If memory serves me right I think he lives in PA. so I'll bet he gets a lot of double takes from other people on the road.
Put your heart into it, well done is better than well said... Ben Franklin