I double checked the distance and according to Selene 53, Mystic Moon's blog, they figure the crossing from Galapagos to the Marquesas is about 3,000 nm and will take less than the calculated 21 days at 6.0 kts because they hope to gain speed with a favorable current and a small sail to average 6.5 kts SOG. In the reverse direction, I would assume the current and winds would work to slow down the vessel. They are carrying 3 fuel bladders totaling another 435 gallons for a grand total of 1,635 gallons on-board. Based off of my own fuel consumption experience with a similar vessel, I would guesstimate their fuel consumption at about 2.5 gph for a single engine vessel weighing about 80,000lb at 6kt, giving them a range of 3,900nm at 6kt, or 3,000nm with 23% spare. This not theoretical. The owners of Mystic Moon are very experienced cruisers with over 20K passage miles.