I saw that you were out on Sunday, but the sea looked a bit lumpy and the visibility was not that good for me going to the wrecks, so I gave it a miss.
The motor getting hot can only be caused by it drawing too much current, that is why Yam fitted the safety cut out. As the motor is still working, drawing too much current can only be caused by,
a) corrosion in the armature bearings, meaning the motor is under continuous load.
b) the motor still having power applied AFTER it has reached its limit stop.