Fuel tanks, Page 2Another interesting situation that I observe on occasion is the presence of huge bacteria colonies in diesel fuel tanks. The colonies present themselves as gelatinous blobs that float at various levels in the fuel, some close to the bottom and some in the middle. In this unusual case I was operating a 1982 42 Atlantic Offshore with twin 3208 Cats. The sea trial was to take us to Newport, a distance of about twenty miles. The sea was almost calm for about half the trip and the vessel performed better than expected at all engine RPM’s. About half way the wind and sea picked up a bit, small sea, about two feet or so. I had already checked out the fuel delivery system before getting under-way, and it was in great shape. As soon as we hit chop of about two feet the starboard engine went back to an idle while the throttle lever was at half throttle. Incidentally, the wind and waves began to increase as soon as the engine decided not to operate properly. We decreased speed and went along for a while on the port engine, which would have been a pain without the auto pilot. Both fuel gauges indicated full, and I knew the delivery system was in good condition, so what could cause the engine to idle. I left the throttle lever in the same position it was in when the trouble began. Believing that the remainder of the trip was going to be a drag I just sat back and watched the sea grow.