Imho, the answer to the question is in the question: "Boat controller". CF sent me the BK marine controller to replace the car one which his junk XLT motor burned up and, of coarse, I ebayed it to try and get some of the $650.00 I wasted dealing with him back. If the Hydra's were designed to work properly in 1/8th scale conversions Castle would have rebadged them, intalled air cooled heat sinks and called them Terra 120's and 240's instead of going through all the trouble and failures with the MMM. There again, just my opinion.