Looking for a 60ft long range cruiser?

I'm a fan, but I'm a bigger fan of Jack Hargrave's work where more living space is available on the main deck without significant changes in elevation as you move from room to room.

It's a personal choice. But my checklist was "few steps", spacious conditioned livability, day head, sea stability, quality construction.

Unless you re 30 years old, steps are knee killers. I used to run a boat where the galley and aft deck were two steps up from the sunken salon. What a PITA, I mean a PITK… by the end of the day. Every time I got back on my own boat, I praised Jack for its flush deck design!!

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.

That's a good summary. I'd add that "no one" is honestly promoting a long range vessel based upon 20 knot performance. Long range discussions are always going to focus on displacement speeds. At 20 knots you're simply discussing the type of range you have, but "long range" really starts north of 1k NM.

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.

Yes, Island hopping, but not requiring fuel at every other island to keep going. And when hopping, likely you're not sprinting to the next stop. But to each their own...

I'm pretty close to .5 NM per gallon, about 15% weight ratio of fuel to gross when full, and I can travel 1k NM. I'm much more of the classic motor yacht (Burger Houseboat by builder nomenclature), so I'd never refer to her as a LRC, but she's a terrific sea vessel, all creature comforts, and can run a long range.

It just seems to me that the marketing allure of circumnavigating inclusive of poles and isolated anchorages has people wanting the taste of expedition. Today's center of that imagery in this size range is probably Nordhaven. I'd take the flat living area of my Burger, although she won't provide me with range to cross the Atlantic.

every boat I ve run has hydraulic pumps on the mains to run the stabs underway. The only time we use the gen driven pump is for the zero speed.

sure a gen will likely be on for air con and whatever needs to be run

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.

Indeed you need stabs to run at displacement speed but it is much more comfortable and smoother than running on plane. With the boats I ve run (84 before and 110 these days) we run at hull speed 80% of the time. Less motion, more comfortable. Same with my personal 53, I rarely run on plane but having the option to do so is nice when needed

running the hydraulics off the mains barely increase fuel burn, certainly less than running a gen. Often you won’t have enough power from a gen to run full load (air con etc.) plus the hydraulics.

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

Odd. Test data Ive seen suggest the near 1:1 ratio is at hull speed, not at 20 knots. At 20 knots the report shows around .4:1.

The new GB85 is highly touted for range and overall efficiency. It's around .4: 1 at 20 knots. At displacement she's around 1.15:1

wishful thinking. 420 gallons and a 390nm range at 20kts would mean about about 20gph combined. No way that’s possible on a 48 footer.

Twin 1000's won't even do that at 1200 RPM. Now, shut down one engine....

actually our 2000hp MTUs burn 22 gph combined at 1100rpm.

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.

Are you suggesting that you require 180 HP per engine to reach 20 knots on your vessel? Or perhaps you need 360 HP from each side for an overall burn double your calculation?

GB85 isn’t marketing the more fuel efficient hull without some evidence. Hull speed consumption of roughly 1.2 miles to a gallon with nearly zero wake during sea trials is telling a story worth at least considering.

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.