Captains,
I have an easy trim tab modification for anyone that has the factory OEM "under hull tabs " .
The factory design is like dragging the open end of a bucket behind the boat at cruising speed . Picture a shoebox lid upside down, the rear most edge is the DRAG POINT,as water rolls over the leading forward edge,the restriction is the approximate 3" high vertical by 50" wide trailing edge that traps the water flow from easy exit .
I molded in a RAMPED trailing edge with aerosol spray exterior insulating foam.(Home Depot, $ 4.95/can ) 4 needed for my 35 ft express .
Use cardboard cut to contain the foamed in area and wrap with wax paper for easy removal.
Let cure for 24 hrs and then use a 7 " steak knife to trim /shape the RAMP,sand and fair in smooth.
When faired in use West System epoxy (butter thickness ) ,to coat over the foamed in area,sand again when cured and then bottom paint .
You should see about 1/2 to 3/4 mph increase .
Tim Toth / Sandusky,Oh