Looking at the directions to mount my quad beam transducer, the picture shows mounting above the bottom of the hull, not flush. Is this correct? My older units in the past have always been instructed to mount flush or just a little below. My brother just finish doing his flush with the hull and has water shooting up in the rear. Something doesn't sound right so though to ask for help. I have the 788 and am putting the quad beam in the rear. I would think I would get interferance from the hull if mounted a couple inches above the bottom of the hull. Appreciate any help.