Looking for a 60ft long range cruiser?

I would just caution the "long-range" qualify which is mostly a marketing term. If you take the Magellano as an example, the boat displaces 76k lb, fuel is 1,000 gallons or 7k lb (9% of displacement), it makes 0.4 nmpg at 20 knots and has a range of 390 nm (being generous here). The Sirena 58 is better at 76k lb, 950 gallons or 6.7k lb (9% of displacement), range is 388 nm @ 20 knots. This is hardly long-range. My Riva 48 displaces 32k lb, fuel is 420 gallons or 3k lb (9% of displacement again), makes 0.9 nmpg @ 20 knots and has a range of 390 nm. Coincidence? No. Design.

The Sirena 48, by the way is particularly deficient here because of all this extra weight. It displaces 60k lb, fuel is 502 gallons or 3.5k lb (6% of displacement) and the range is only 250 nm @ 20 knots.

So, if you want long-range, you need to increase the share of fuel from 9% to say, 20-25%. Increasing fuel to 25% of displacement without affecting handling means that you have to save on other tankage (reduce water, rely on a watermaker, keep the other tanks empty), reduce weight (eliminate fancy and heavy convenience items) and install bladders. Probably eliminate the flybridge as well. Most people would not want to part with the amenities because they determine the quality of the long-range experience. So, it is a trade-off. I do not think you will find many standard boats with such high tankage because it is just not needed most of the time for regular crusing.

I have some second thoughts about this. These boats will achieve 1,000 nm at displacement speeds, 1 nmpg, so this means they use 8 gph. Then you would probably use 2-3 gph for the generator to run the stabilizers since it is painful without them at displacement speeds. So, the range drops by 20%. I would say long-range cruising at planing speeds could be quite enjoyable. Long-range is not necessarily crossing large bodies of water. It is more island hopping and exploring without the need to refuel but you do want to run fast if the boat can. So, I really think that it is about weight minimization.

Pascal, that is not the point. Stabilizers require energy and you can provide this energy from either a separate generator or increased fuel consumption on the main engine. The point is that voyaging at displacement speeds is uncomfortable without stabilization which can be achieved with with stabilizers or much increased weight (trawlers) and this reduces nmpg. This is why trawlers like Nordhavn which shoud be able to achieve 1.5-2.0 nmpg, post actual fuel consumption closer to 1.1-1.3 nmpg. My thesis is, get a slightly smaller boat at go at planing speeds which is faster and more comfortable as long as you can fit enough fuel. There has to be some optimal size for a planing boat that allows you to carry 20-25% of displacement in fuel while providing for all the amenities that people require.

Riva 48 getting 0.9nmpg @ 20 knots. Wow. That is one efficient set up, no?

You guys may be right that 0.9 nmpg could be optimistic. I am pretty sure that once I run 350 nm without refueling and had fuel to spare on the other end. May be the tanks are bigger than the stated 420 gallons.

But let's try to bring some math into this. Crouch's formula says speed = c/sqrt(weight/hp). The constant c is hull dependent and I believe it has a lot to to with the transom angle. So, I look at my actual max speed of 31 knots = c /sqrt (32,000 lb / 860 hp). So, C =189. The weight is as measured by the boatyeard lift, the hp is max for the 2x 6CTAs. Using that c, I get 360 hp required to push the boat at 20 knots. One gph makes 18 hp, so 360 hp needs 20 gph, hence about 1 nmpg or at least in the ball park, less with full tanks.

Applying the same math to the Magellano 60, 26 knots, 76,000 lb, 2x 730 hp gives you a hull constant of C=188, exactly the same as above and fuel consumption at 20 knots, tested in the magazines 50 gph, calculated at 18 hp/gph = 48 gph or 0.4 nmpg. So, the math works exactly.

Applying the same math to the GB85, 25 knots, 115,000 lb half load, 2x 1,000 gives you a hull constant of C=190, wow, the same as above. How interesting. Fuel consumption at 18 knots is given as 58 gph, calculating using the formula above @ 20 hp/gph (more efficient engines), gives you 64 gph. In the ball park. It is 10% more efficient but it is not clear if it is due to the hull or just the higher efficiency of the turbo diesels because they are larger engines. And, note the deadrise - 5.5 degrees.

Again, I think all the differences between boats go down to displacement, and to a much lower degree, the transom angle (flatter is more fuel efficient and less seaworthy). Every boat review in a magazine starts with "This amazing boat has a new optimized and more fuel efficient hull... whatever" that is just marketing. Do we really believe that hydrodynamics has changed in any significant way in the last 50 years? It is all about a designer choice, weight vs. transom angle. It is totally OK to say, I need more superstructure, more amenities and this makes me happier, so I am willing to accept by 2.5x reduction in fuel consumption. But is it not OK, in my opinion, to market a boat as as having a more fuel efficient hull when it is about the weight.

Pizzazz7, you have the experience, the calculations are fine but there are so many variable that are not accounted for in many calculations. Sea state, current, wind to name a few. It's all good, I am glad you are getting 0.9 @ 20kts.