< So I think you need to be long, narrow and "light" to achieve the higher fuel numbers we see from the unsailboat and others who get or claim higher NM/G. Perhaps a better metric is tons/waterline, aka length/displacement. We're 52' WL so we're .88 tons/ft. > I believe narrow and long works, but so does an efficient whale type underbody. My parents had an Angel Marine 62, 61 LOA, 50.5 LWL, 17.5 Beam, 5.5 Draft, aprox 50 registered net tons (volumetric measurement). She did 8.5 with two 3208 NA burning twelve gallons or so. Another Asylum is 60 LOA, 52 LWL, 17.5 Beam, 5.5 Draft, but 64.95 net registered tons. Burns 5 GPH at 8.2 with two Volvo Tmd 70B turning 1400 rpm - real world numbers after 4500 miles. Same size boat, the one a semi-displacement hull not running very efficiently and the other a full displacement. Mine is a heck of a lot larger in terms of volume and freeboard, hence windage, yet gets several times better milage. Both are probably about the same displacement as mine is all cored and the Angel was lots of solid glass. Bob Phillips, Another Asylum, Tortola, BVI