Hi Arild - Congrats on the new job! Must be nice to work in a NA office. I worked with some of those folks and long ago was a member of SNAME myself but let it lapse. Amazing stuff, what those guys know. We like the two tank system much better than the one on the sailboat, where we have one large center tank and two smaller wing tanks to feed the main. Here is how we manage our two-tank FO system on Seahorse: Our P&S tanks are 835 gallons each located under the galley sole forward of the ER. At 7 knots and 2.2 GPH we can travel far and can't see a difference that the extra 5 tons makes. But our prismatic is better than that of a trawler hull. Management is easy - we supply the ME from the stbd tank and always transfer to it from the port tank. Reason being that we have a slight list to port with equal tank levels and so use the fuel to keep an even keel. Transfer takes place through a Racor 800D recycler/blender, so the fuel in the stbd tank is always water-free and clean to 10 microns. Filling only one tank from shore makes fueling easier. There is also a 40 gallon day tank aft, filled via a separate line from the Racor. That tank serves the heating plant and the pony engine, but can also feed the ME if needed. We don't have a problem with condensation because the tank tops are below the waterline and so the temperature is stable. We really think this concern with condensation from "breathing" moist air through the vents is overblown. Seahorse is out of the water for 4-5 months a year in North Florida where, in winter, there can be large temperature changes daily, and we have never had a problem with condensate. We think this particular bit of concern comes from metal boats with skin tanks. We stopped using Biobor and the like years ago and have never had a problem with the dreaded critters. Biobor has problems of its own. A while back someone mentioned getting a desiccant cap for the vent on a hydraulic SG tank. Sounded like a good idea to me. Our tank is in the ER, and the oil temp runs about 160F. Must be some water in the bottom, I thought, as I had neglected to check since buying the boat almost 3 years ago. There wasn't. Regards, John "Seahorse" > Scott, you have touched on a key point. FUEL MANAGEMENT and tankage arrangement should be one of the key design elements when considering a vessel design. Having one or two large tanks may prove a handicap in dealing with a large quantity of bad or questionable fuel. Several smaller tanks may be a better bet despite the increased cost of additional piping and valves. ************************************** Get a sneak peek of the all-new AOL at http://discover.aol.com/memed/aolcom30tour

The Willard 40's had an interesting tank configuration. Rather than positioning the tanks as saddle tanks (outboard of the engine), Willard took a different approach: two thwartship tanks located midship, more or less beneath the pilothouse area (or lower helm on the sedan models). This greatly lessened the trim issues, either P/S or fore/aft. But it also creates a cavernous engine room - full width!!! The down side, especially on the Pilothouse model, is the companionway forward is far forward and slightly compresses the staterooms. But it does provide decent sound insulation for the sleeping area. Plumbing is also greatly simplified as the outlets for each tank are near centerline - within a foot or so of each other. Site guages are also side-by-side and easily viewed. Overall, I like the configuration alot - and am curious why it hasn't seen greater adoption. Willard managed up to 700 gallons in this configuration. A trip I did last year aboard Patrick Gerety's 2001 W40 from Long Beach to La Paz on the Baja-ha-ha saw actual performance of under 1.5 gph at 7.2 knots - well over 3000 nms range at a standard cruising speed. Peter W36 Sedan San Francisco