Correction of a balance problem is not so much different than working out the issues on the elementary school playground teeter totter. If one side is overloaded, there are just three choices. Lift on side of the heavy guy, add some load to the light side or for some of the fancy ones, move the board off center.
From the physics angle, the motor weighs 420 pounds at 7.5 feet from the center of gravity, which creates 3150 ft-lbs of torque backwards. The first and easiest change was to move the battery position from back near the motor to the front of the boat. It weighs around 50 pounds, and by moving 10 feet forward, will exert around 500 ft-lbs forward rotation.
Second, since the seats were not permanently set, I was able to move them forward one foot. It is a small change, but does contribute to some forward torque at rest and around 6-800 ft-lbs with a load. Third, it is not uncommon to add water or sand ballast to some boats, and the float test below shows the model loaded with 120 pounds near the front.
If the model test is accurate, it is getting nearer the objective of only a slight up-angled deck. I am also investigating ways to add floatation at the back, which may take the place of needing to add extra weight in front.
The sketch below shows drawings of some experimental stern extensions to see if there was any good way to add buoyancy to the back. It is probably overdone, but I like how the design adds some dimensional depth to the side as well. Of course, it will be important to make sure the angle of entry is still okay with any added width. This is obviously not an interactive blog but I do invite any input about the hull shape.
With the buoyant sections, change in position of the battery, seats, and optional ballast, I believe we are off and running again.
Commitment is the unrelenting push to keep seeking solutions when problems arise.