Cutter motor cutoff at 2am grounded us for a full day

Last Tuesday we were running steady near the mouth of the Sabine River when the cutter motor just shut off, no warning, no breaker trip we could see. My first thought was the VFD overheating because we had been pushing hard through some stiff clay all afternoon. Turned out it was a corroded terminal block on the motor junction box, salt air had gotten in behind the rubber boot. Took me an hour to find it because everything looked fine until I wiggled the wires and saw the arcing marks. I cleaned the contacts, hit them with dielectric grease, and put a new boot on, but we lost the whole next morning waiting for a parts run to Port Arthur. Since then I check that boot every time we flush the deck, takes two minutes and beats a 12 hour shutdown. Anybody else had salt corrosion sneak up on a component you thought was sealed tight?