I believe that is a perfect description for the mechanic that was hired to "professionally maintain" our current boat. The broker is notorious for using some of these locals for hands of owners, instead of the higher paid marine mechanics.
I do recall that the guy I paid to troubleshoot and repair the Yanmar on the Islander after we sold it charged $80 an hour. That was a $600 bill but Matt the new owner and I are still friends and it was the right thing to do. Seal in the fuel pump went bad over the winter BTW, didn't get ugly until he was motoring out of our club after taking possession.