The Perfect 60' to 65' Cruising Boat

[Matt Johnson]

There is a Carbon Bill Tripp 65' with dinghy garage on Yachtworld. 44k pounds of speed!

Matt

[accomplice]

Originally Posted by Dockhead

Yes, I do. If it were not so, then racers would not be obsessed with weight as they are. The heavier boat in your case will be carrying more wetted area in the same waterline length so will be slower with the same SA/D. It would be otherwise if the waterline length were lengthened proportionately, but we have agreed that this is all good -- that's the whole idea of bigger boats.

Assuming all else is equal, two boats with the same SA/D will have the same SA to wetted surface (under flat water, low wind conditions, wetted surface area will determine drag) and therefore the same speed. The waterline length determines the hull speed (maximum), and is independent of displacement for displacement hulls.

If that doesn't make sense at first blush, consider that wetted surface area generally goes as the square of any linear measurement (think of the surface area of a sphere or cube), whereas the displacement goes as the cube. Thus wetted surface increases more slowly than displacement as displacement grows -- as the 2/3 power, actually. SA/D is generally calculated where the denominator is the displacement to the 2/3 power. Thus SA/D is a proxy for SA/wetted surface area, assuming comparable hull shapes.

... didn't you sail your previous, smaller boat harder?

Yes, I did -- perhaps mostly because the conditions that are pushing my new boat harder are more terrifying and things can go more horribly wrong than conditions that were pushing my old boat. Also, most of my sails on my old boat were daysails (or day-sailing on a multi-week cruise), now the majority of my miles are covered on multi-day offshore passages. When I knew I was 25 miles from my home port, I might tolerate beating into the wind for a few hours to see my family that night. Now, if I'm many days away, I'll find a different way.

This is why folks in the pacific headed from Hawaii to the US West Coast often sail far north, out of the way, to find favorable winds and currents; it is why people leaving Florida for the Eastern Caribbean head out to I-65 before heading south -- there are often more pleasant ways of getting from point A to point B than a straight line.

I'm not saying speed doesn't matter, I'm saying it is one of many factors. Comfort and safety are right up there with it. Depending on the crew and the voyage, they may even be more important. Racers often compromise those other factors, figuring their advantage lies that compromise -- giving up comfort for fame and compensating for safety with skill and luck. I prefer not to lean too heavily on either skill or luck.

[IdoraKeeper]

Originally Posted by Dockhead

Well, getting quarts into pint pots is the essence of engineering, isn't it? If quart pots were lying around, there would be no need for any effort in design, right?

As to crew -- I have no aspiration to having a professional skipper. I'm the skipper, and don't intend to give up my position. More of a Boat Boy, jack of all trades, great at fixing things, taking the odd watch, sourcing parts in port instead of me . I think a pipe cot will be fine

I think auto complete got you. I think you trying to say Boatman not boat boy.....I don't think he will go for a cot but let's ask him. If you keep this up your boat will wind up at Pitcairn.

[noelex 77]

Originally Posted by Dockhead

On the contrary, a faster boat with a lighter, more easily driven hull, can be sailed with an extra reef with better effect and less damage to your forward progress.

I think this is a great point.

People often comment about the difficulty managing a larger sail area. However, a large yacht has larger range of windspeed before it needs to reef.

Put in a reef and due to the longer waterline length it is still making higher average speeds than a smaller yacht with full sail. A large yacht with a reef will cope with a very large range of wind speeds. A smaller yacht will be alternating between full sail and triple reefed over the same wind range to try and match a similar overall speed. This is a lot of work.

If you want to go "x" knots the easiest, least stressful way to achieve this is usually with a larger yacht and a conservative sail management.

Of course with a large yacht you also have the option of going "x+" and who can resist that

[poiu]

Dockhead, have you noticed the whole dialogue about the perfect cruising boat has changed to one of speed and predominantly close haul speed. I wonder if what would really make you happy is if you could go faster upwind,i.e. at a faster vmg?

If that is the case then there is a lot you can do with what you have. Flat sails is first and second. Alone they will give you 10+ Deg tacking angle improvement. Ideally get 3DI and a full vertical batten furling main. A deeper thinner keel (there is a place in Cornwall who could make you one. I have their details somewhere). Polished racing hull paint, flush through hulls. Remove windage and weight such as davits and dinghy. Maybe carbon mast and rigging. Not cheap, but a tiny fraction of the costs of a bigger boat. You will need a bigger boat to reach faster as hull speed is the limit there, but that doesn't seem to be an issue.

[savoir]

You might be just a tad optimistic about the benefits of flat sails. Maybe on a Gunboat . . . .

[weavis]

https://www.youtube.com/watch?v=3F6X7mAKvzo

[DoubleWhisky]

Originally Posted by weavis

This one:

Jeanneau 64

is at least in desired size bracket, but both are not in Dockhead't taste...

[Kenomac]

In the Jeanneau 57, I just see many design issues which don't make any sense for our use. A nice looking boat, but many important things are cheapened in order to reach the price point, such as having an electric furler for the headsail instead of a hydraulic unit. Electricity and salt water don't mix well on the bow.

[DoubleWhisky]

Originally Posted by Kenomac

In the Jeanneau 57, I just see many design issues which don't make any sense for our use. A nice looking boat, but many important things are cheapened in order to reach the price point, such as having an electric furler for the headsail instead of a hydraulic unit. Electricity and salt water don't mix well on the bow.

At least if You do not have Reckmann (for example) electric unit with the motor safely mounted under the deck

Cheers,

Tomasz

[weavis]

Originally Posted by Kenomac

In the Jeanneau 57, I just see many design issues which don't make any sense for our use. A nice looking boat, but many important things are cheapened in order to reach the price point, such as having an electric furler for the headsail instead of a hydraulic unit. Electricity and salt water don't mix well on the bow.

Lots of boats with electric furlers out there. Not sure the problem is as big as all that. Id prefer hydraulic myself but it wouldnt bother me overmuch..... Better that than in mast sails ........... Now there I have seen some problems when something breaks.

[Kenomac]

I realize that not everyone can do this, but if boat speed is an issue in a perfect 60-65 ft cruising boat design, much of this can be solved by watching the weather and planning accordingly; which most cruisers seem to do, us included. Usually we're not in a hurry, and with the exception of sailing in Southern Spain where there's no wind during the summer, we sail almost exclusively, many times using just the headsails alone. Just need to wait a day or two sometimes or leave earlier for the right window.

[Dockhead]

Originally Posted by poiu

Dockhead, have you noticed the whole dialogue about the perfect cruising boat has changed to one of speed and predominantly close haul speed. I wonder if what would really make you happy is if you could go faster upwind,i.e. at a faster vmg?

Yes. That is what I realized this summer. Purely mathematically, taking any random destination and any random wind direction -- the true wind is ahead of the beam in 50% of cases, and the apparent wind more than that. Your destination will be too much upwind to lay in one tack in what percentage of cases then? If you tack through 100 degrees (COG), which is really good for a cruising boat, then that's 27% of all cases.

Add to that the fact that in stronger conditions you can't realistically motor upwind (in a normal sailboat).

It means the following: If you are a long-distance sailor who wants to get places, you have only two choices: (a) a powerful motor-sailer; or (b) a sailboat which can make meaningful progress to windward over a reasonable range of conditions. I've defined this for myself as 5 knots VMG to windward, or 120 miles per day, in 12 to 30 knots of true wind.

If you can't get to windward one way or the other, then you can't go where you please, and this is a serious flaw in a vessel for a serious, long-distance sailor who can't just wait around waiting for the wind to change.

So the discussion of the ideal large cruising boat started to concentrate on this because it is that part of the performance specification which is hardest to fulfill.

One thing I have taken away from thinking about this is that powerful motor sailers like Nauticats start to make a lot of sense. I think it's far easier and far cheaper to solve this problem with brute force engine power, than it is with high sailing performance.

So another logical consequence is that even if your primary way of making miles to windward is high sailing performance (the way I would do it), it probably makes sense to equip the ideal 65' cruiser with a powerful engine, more powerful than you would typically put in a normal sailboat. A boat of this size won't notice the weight of a bigger engine, if it's a modern turbocharged engine. I think this is the idea behind German Frers' Halberg-Rassey 64, which has 300 horsepower versus 180 horsepower in the similarly sized Oyster. And in a more easily driven hull with 17' beam, compared to 18' in the fatter Oyster. I think you could power your way through quite a significant sea state with that setup, and it would be great to have that option. The boat doesn't actually need to be a motor sailer to have this kind of capability -- just a big enough engine.

[Dockhead]

Originally Posted by Kenomac

I realize that not everyone can do this, but if boat speed is an issue in a perfect 60-65 ft cruising boat design, much of this can be solved by watching the weather and planning accordingly; which most cruisers seem to do, us included. Usually we're not in a hurry, and with the exception of sailing in Southern Spain where there's no wind during the summer, we sail almost exclusively, many times using just the headsails alone. Just need to wait a day or two sometimes or leave earlier for the right window.

This is a question of latitude! In the Med, you never have to wait for as much as a week for the wind to change direction, or at least, to drop to a calm, and a calm is fine, because you can just motor.

Up here, it's not like that! Up here, the wind may blow hard for a month from the same direction. May and does -- that's the way it was this year. Last two or three weeks of May we had persistent NE winds of F5 - F6 and occasionally more. And in August, it blew pretty hard from the SW the entire month.

That's the essential challenge here.

[Dockhead]

By the way, here are the polars for the HR 64:

HALLBERG-RASSY 64 SPEED PREDICTION DIAGRAM.pdf

It shows a lot of boat speed in all kinds of different situations. I wonder if the boat really achieves this.

At 32 degrees (apparent I guess?) in 20 knots, 7.5 knots of boat speed.

I reckon that should easily amount to 5 knots VMG to windward. If the boat really achieves its polars.