Just for information purposes, I recently helped a friend redo his Sea Arc same boat as yours. Completely dis assembled rewired with new seat bases and carpet. The foam is nothing but blocks of open cell foam just cut and shoved in every nock and cranny. I doubt it is water logged. First thing I would check would be to see if motor is mounted square on transom. I also doubt the dents would affect it. Probably a unique characteristic to that hull design coupled how you might have it loaded.
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Charlie Weaver USN/ENC 1965-1979
My guess would be motor tucked into transom too far. Power trim? Trim it out. If not move the pin one hole away from transom. Also look at the "torque tab" under the anti-ventilation plate. For a boat wanting to go left you want to turn the tab CCW looking from top. (moving front of tab to the left)
If the boat is not listing while stationary then it is unlikely a weight issue.
Yes bad dents can cause the stern to force bow down causing it to suction to the water & not break loose. Do you by chance have a hydrofoil on the motor because they can cause the exact same issue with forcing bow down. Been there done that.
Can you post a picture of the dents? I’m just curious how big they are.
“You know the thing about a crappie…..he’s got black eyes, lifeless eyes…like a dolls eyes.”