"A commercial fisherman in the Seattle area gave some suggestions but one thing he said that I am unsure of is the location of the fuel outlet. He said to place the fuel outlet at the bottom of the tank rather that a pickup located on the top, with a tube extending to the bottom of the tank as is more normal." As far as I'm concerned, the only reason to have the fuel line coming out of the top of the tank is to meet legal requirements in some places. The authorities say that if the line breaks or leaks, fuel might leak into the bilge and blow you up (this is primarily a concern on petrol engined boats rather than diesels, but heaven forbid we should blind Big Brother with science). Of course if a top-exit fuel line breaks anywhere below the fuel level in the tank, fuel will still siphon out and into the bilge. So to prevent that you're supposed to fit an "anti-siphon" valve (something else to go wrong) into the line. If the anti-siphon valve leaks, it can allow air into the fuel line with the predictable results. Technically speaking bottom exit is simpler and makes it easy to fit a sight glass and drain-off tap to remove water. Ideally however the drain-off tap should have its own connection to the tank slightly below the fuel line to the engine, but I've heard that even that is illegal in some places. In the days of my youth I did a lot of SCUBA diving from small trawlers off the coast of Scotland and the Hebrides. As I recall, every one had the fuel line coming off the bottom of the tank, and it sounds like your fisherman agrees. But hey, what would professional seamen know? The man from Canberra (or Whitehall, or Washington DC) knows best. Regards, Robert Bryett Sydney, Australia. mailto:rbryett@ibm.net