After reading your previous thread, It had occured to me that they may be some binding in your drive system. And that the extra friction would cause the motors to work harder and draw more amperage.
The Weeds would easily explain why the motors would come in hot, and the wires nearly fried.
A fuse should prevent this from happening, but it may also require you to go for a swim, or use some other type of recovery system to get the boat back should such an incident occur again.
