Same on my boat which is a 42' with twin diesel. As best as I can calculate the miles/gal is about the same between 11-16knots. Below is better, above is worse.
The only real difference in that range seems to be overall weight which is in large part a function of fuel and water load. I have 4 fuel tanks (fwd-50gal, aft 50gal, and saddle tanks at 150gal ea.) and 175 gal of water under the aft cabin bunk. The farther forward the weight the better so I manage the aft water load, keep the aft fuel tank empty and use the forward fuel tank as the emergency reserve should I screw up on the saddle tank load. Thanks to Waggoners (a good Northwest boating journal) you know the weight of one gal of water is 6.2lbs and diesel is 6.7 lbs. Doing the math my fuel weight can be as much as 3,350 lbs and water 1,085 lbs. That's a lot to haul around. There is some good news. The extra weight seems to effect the mileage more the faster you go, so - I run fast and empty as possible to get to the islands then fill up and cruise slowly around. It works perfectly for the northwest where there are lots of choices once you reach your destination area. The big negative is fuel price differences. This summer, fuel in Seattle was $2.75 as I left. The farthest point north I traveled in Canada it was $4.40/gal (all adjustments to US $ made). Kinda suggests you stay close to home. Any other fuel saving suggestions? Drift with the current? Anything but buy a sailboat - please. -- You received this message because you are subscribed to the Google Groups "UnifliteWorld" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/unifliteworld?hl=en.
