I measured mine this weekend. Leaning over the motor to measure (200#), the top of the mounting board was 13" off the water. Keep in mind that my Ariel has a lot of weight (120# of lead and 70# of sand, plus furnishings (anchors, lines, etc. beer, etc.). My Yamaha is a long shaft

My recollection is that when I rebuilt Solsken, I determined the height of the mounting board (which is 1 1/2" higher than the original board in the well) by taking the lower edge of the boottop as the water line. Then I determined where the waterline on the motor was supposed to be. Working up from there told me how high the top of the mounting bracket/motor board was supposed to be.