boat or motor spray

I have a 2007 Crestliner aluminum fishing boat(20 ft.) powered by a 225 Merc outboard. Since it was purchased, the passengers in the rear seats, and to some extent the driver and other front seat, get soaked from water spray coming from the stern area. The dealer has adjusted the height of the motor on the transom. which helped a little, but the problem remains. Both Crestliner and Mercury have been of little help, except to suggest the motor be remounted higher. Any suggestions?