the primary reason for setback is to adjust the center of gravity of the hull so it is just in front of the center of pressure on the pad. This is the balance point where the trim angle required to hold the bow up is minimal. If you go back too far, the hull will become unstable at medium speeds and porpoise badly, and you will need negative trim to hold the bow down at high speeds. Now think about this for a minute. Why would an R-boat need to move the motor that far back to properly balance the boat and motor on the pad? Perhaps a tad heavy up front? BTW there is also invisible setback as well, as everyone today uses a notched transom (I think this was a Skeeter idea but am not sure). This just cuts the pad off before it reaches the transom, which is just like the jackplates, the extended transoms, etc. There are other advantages as well, such as getting the prop farther away from the trailing edge of the pad, which puts it into cleaner water as opposed to the well-aerated water coming out from under the hull. And letting you raise/lower the motor to optimize the gearcase/prop depth for optimal performance. But balance is key. Nose heavy and you need excessive up-trim to hold the bow up, which wastes thrust. Tail-heavy and it will be squirrelly (done that in years gone by when experimenting). As you approach the perfect balance point, you will start to develop porpoising as you come off plane gently…2008 Pantera Classic2014 Mercury Pro XS 200
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