RE: Rio EP stabilization
Rigger sponsons help reduce effects of motor torque while the boat skips along with minimal contact with the water. Also, the stuffing tube is off-center to help alleviate prop walk. Your Rio needs a certain amount of contact with H2O for stability and will suffer more from these effects. Adjusting the cog (battery placement, etc), trim tabs and prop choice will help the Rio, but may not catch the rigger!