not sure if any one has done this but i slightly detongued the stock prop on the
b26 and went over the entire prop with some fine sanding paper and made it as perfect and smooth as i could. Im still running on nimh but the difference was quiet noticable. The water was very choppy so after a fairly good run i went to a nearby canal were it was calmer and it went very quick but i didnt have a gps so sorry no speed but i guess it would be as fast as you can with stock plus it doesnt cost anything to do