The load was 3 people and a battery.
are the shawnee 48"ers really that much slower? there is an extreme distinction between nowhere near planing and planing in less than twice a boat's own length and it doesn't make sense to me that an extra 4 inches of bottom width would be responsible for that difference.
To reiterate my original questions:
At what speed will a 10 or 15 prop motor push a heavily loaded river jon?
how big are the speed differences between say a 42 and a 48 bottom?
what about one with just 2 people aboard?
How much rocker does a shawnee have.
I use the term planing differently than normal powerboaters do, i simply mean any normal, sustained instance of traveling faster than hull speed other than plowing. a boat with a hull speed of say 5 knots traveling at 9 to 12 knots semiplaning on its midsection instead of the stern, but reasonably level and not throwing up a huge wake Would count under my standards, and in fact is the very behaviour I am seeking.
An interesting story I once read (I forget where exactly) involved a smart little stunt in Louisiana involving a restored cypress Bateux and a girl on waterskis. Apparently the 24 footer dragged the (110 lb iirc) girl onto ski at 12 knots and without towing her could make 15. the engine in question was an 8 horse Nadler inboard from the 1920s. I find this surprising but believable because I have seen video of a very similar boat with the exact same make of engine planing long before full throttle.
your math is flawed. The boat is 6" wider. a 48" wide boat has a surface area 84 sq/ft, a 42" wide boat has a surface area of 73.5 sq/ft.
I have a true flatbottom monark that is 18x36" and my 9.9 will gps at 17mph with a 9 pitch and 14 with two people. the same motor on my old boat wouldnt even plane out. It was a 15' x 42" fiberglass boat.
I have piloted a 21x32 shawnee and a 21x48 JS boat, both with 9.9s and the speed difference is tremendous.
The river boats used on the white are not planing hulls.