Combined. See my last reply. I never include gen because i run the gen 24/7 so I keep track of that burn separately. the key is to not exceed hull speed. For a 67 footer hull speed is going to be 10kts. Not 10.5 kts… an extra 1/2 kts above HS will Cost you 30% more fuel. An extra knot? Close to double
Hull speed can be calculated by the following formula: v h u l l ≈ 1.34 × L W L {\displaystyle v_{hull}\approx 1.34\times {\sqrt {L_{WL}}}} where L W L {\displaystyle L_{WL}} is the length of the waterline in feet, and v h u l l {\displaystyle v_{hull}} is the hull speed of the vessel in knots
I wholeheartedly appreciate your willingness help and give me some numbers to go on. Im a diver and the ability to use it as a live aboard not to mention a dive boat or occasionally as a chartered dive boat and run it kinda affordably, I’m not expecting a half gallon an hour, is rather important. I’m wanting the yacht equivalent of a Chevy suburban. The places I’d like to go in the Caribbean and gulf are far enough out I don’t want to do it in a 30’ bathtub.
Any idea what the Detroit 12V-92TA 8122-7400 rated shp 775@2300 rpm would burn at 1800rpm cruising? Cant find any performance data on this engine.
