A friend has a sailboat that has a diesel engine as a secondary power. He also has a filter set up that is independent of his machine, that pumps the fuel out of the tank and through 2 or 3 filters (don't remember which) and back to the tank. He runs that for an hour or two and it removes all the water. He refers to it as a fuel polisher. When I removed the inground tank at the house, he used that to pump the tank dry, and it does a fast job of moving the fuel oil from the tank to 55-gallon drums.