I have a Hewes 20' SR soft top and am debating what to do for heat. I am shying away from propoane & alcohol because of the moisture content. Has anyone installed a deisel heater in a soft top before? I am considering an exhaust/intake penetration just below the gunwale on the port side between the front & back seats. I have about 33" of freeboard, so the penetration would be around 29-30" above the water line. What'd ya think? Is this doable, or foolhardy?