Did you sample the mud pool in Vulcano? After two weeks of showering in strong-smelling soap, we still reeked!
It transpired that the starboard alternator, although Caterpillar, was not the original and the shaft was the wrong size for the pulley and nut. The pulley came off and disappeared into the bilge and Tom had to perform some contortions to locate it. In the process, it stripped off the water pump belt. Fortunately, we had replacements. In the end, we removed the suspect alternator and ran on the port one, which appeared to be charging both battery banks. The batteries were new, so no problem there.
Actually, it didn't go as well as my Camargue 47, which had the same engines. However, it was in need of some TLC after being laid up for so long and Tom intends to bring it up to scratch this winter. As I said, once we got going, the Cats didn't miss a beat.
My Camargue Cats never had alternator problems. In fact, the only problem I had in many, many miles was having to replace the aftercooler flanges with bronze ones, and that was a precautionary measure.