Is this the jack-plate you are talking about: https://www.google.com/products/catalog?hl=en&q=JP-4FA&um=1&bav=on.2,or.r_gc.r_pw.&biw=1920&bih=1075&ie=UTF-8&tbm=shop&cid=12886628096688729612&sa=X&ei=VIQdTvvnOoqcgQe0vpDrCQ&ved=0CE4Q8wIwAA
How does the "Flat" bottom handle at speeds of 40mph?