Fascinating! I always believed the myth that you couldn't have drains below the top in diesel tanks. I once owned a British boat that had the tank mounted under the cockpit with a bowl in the bottom of the tank like the one in the Buehler article, and it worked perfectly. It was good for not only draining off any water that would get in the tank, but also every spring I would drain out any crud in the bottom of the tank. Plus, the tank was gravity feed to the engine, so the fuel pump wasn't strictly necessary. I know in the past the old British books used to always talk about pumping fuel up to the day tank from the main tank, which might be lower than the engine. It meant that you would always be taking fuel off the top of the main tank, and then off the bottom of the day tank with its water catchment bowl. It meant you had very little problem with contaminated fuel. Fantastic system.