Jimmy Lewis U-BoatThe U Boat is the fastest smooth flat water board on the course. This year weve done some minor changes in the shape that resulted in major performance changes. The most noticeable change is the wider tail block. This increases the stability dramatically. The rails in the back are harder too which also adds to stability and makes for quicker water release. Like the original U Boats these 4 new models have the Jimmy Terrell inspired square type concave