Who said this aabout modern yacht designs?

[dom]

Most designers calculate empty displacements for stability purposes, (sans safety gear et all and sometimes without furling systems) and most manufacturers like to quote these numbers in their publications. Remember, heavy = bad. This is how the yachting press "tests" these boats as well.

...If, as I have said before, a lot of nonsense has been written about sailing speeds, generally by over-exaggeration, displacement has to be a close second by gross understatement.
Fudging the numbers on speed? Who cares. Fudging the numbers on displacement is a lot more sinister: it not only affects speed (Nooo!) but more importantly, stability, safety and sea-keeping.

Regarding stability, no adding weight is not always bad for stability and it is nonsense to say so.

Think of water and fuel tanks carefully moulded to fit shapes close to the bottom of the boat. Or engines, batteries, generators, indeed anything bolted down or otherwise firmly secured below the centre of gravity. Which is why ships take on ballast for ....erm heavy weather

Weight up high on deck or aloft is another matter. All explained in Figs 3 & 4 in the attached MCA link on Fishing Vessel Stability, which is well worth a flick through for anybody interested in stability:

https://assets.publishing.service.g...CGA-Fishing_Vessel_Stability_Guidance-WEB.pdf

 

[Laminar Flow]

Fair enough having different points of view, but posting nonsense while claiming elsewhere to be a boat designer is not really on.

The capsize factor you refer to is simply beam/(cube root of displacement)

So add 1000kg to the bottom of your keel and it goes down; fair enough. Add it to the top of the mast, ditto! Now does that make sense?

Well, I never claimed to be a boat designer. I have designed and built boats; I would call myself an interested amateur. Ted Brewer, who published the capsize screening factor as a basic tool to assess offshore suitability, is a professional, well-known designer; I have met him personally and I did not have the impression that he was spouting nonsense. You could also read up on Marchaj's excellent book seaworthiness for some more in-depth info.

 

[Laminar Flow]

Regarding stability, no adding weight is not always bad for stability and it is nonsense to say so.

Think of water and fuel tanks carefully moulded to fit shapes close to the bottom of the boat. Or engines, batteries, generators, indeed anything bolted down or otherwise firmly secured below the centre of gravity. Which is why ships take on ballast for ....erm heavy weather

Weight up high on deck or aloft is another matter. All explained in Figs 3 & 4 in the attached MCA link on Fishing Vessel Stability, which is well worth a flick through for anybody interested in stability:

https://assets.publishing.service.g...CGA-Fishing_Vessel_Stability_Guidance-WEB.pdf

Adding weight will increase initial stability. I never claimed otherwise. Beyond that, I suspect you might be very surprised where the centre of gravity is located in a modern, beamy, light displacement hull. Very little of what is loaded will actually be below the CG and this, undoubtedly, affects ultimate stability. Again, you might want to check this up in Marchaj's "Seaworthiness".
Comparing a sailing vessel's stability requirements to that of seagoing ships ... well, for one, there is the matter of scale to consider. Waves are the main contributor to capsize. It is generally acknowledged, that a 30' boat could be capsized in ten foot seas; or wave height equal to 30% of length. At this point ultimate stability is of paramount concern and wide and flat just does not do well here.

 

[Laminar Flow]

I don't even know who you think you are arguing with any more.

Nothing you say about the Pogo simply being a light boat is in any way disputed. That's the whole point of the design. The post of mine you quoted even starts with me saying "There's no doubt that to get the best out of that type of boat you have to keep them light. "

The point of designs like the Pogo, and there are many others, is not that they are magic, but just that they bring a different approach, a different mentality, to going cruising. The idea that a modern cruising boat can plane. Clearly it's not for everyone, very obviously it's not for you, but I have no idea why the very existence of these boats seems to upset you so much.

Here's a nice review of another boat that you'll hate. A boat that was tested straight after an Atlantic circuit. The quoted performance, albeit in light airs, is very impressive indeed.

JPK 45 boat test: Performance cruiser provides memorable enjoyment

I'm sure the JPK is a fine boat, unfortunately I have not been able to find enough technical data yet to form a good opinion. There is no doubt, that given enough SA most boats will perform well in light airs. Judging by the pics she probably has a fairly high SA/D ratio and clearly has enough beam to stand up to it.

P.S. I do not "hate" any boat in particular. I try to form my opinion on the obvious technical aspects of a design and for what it is, or was, intended. I have also been very critical of what, I perceive and have experienced, are short-comings in some much more traditional designs.
I am however frequently amused, when some designer has managed to re-invent the wheel and the hype that ensues over it in the press. Just as I find it ironic, when a two hundred year-old gaff fish boat design with leeboards, beats a modern centreboarder with a modern rig, both out-footing and out-pointing it. It doesn't make me want to run out and buy a Lemsteraak, but I sure as hell want to know how it is possible, technically speaking.

 

[dom]

Adding weight will increase initial stability. I never claimed otherwise. Beyond that....

Ergo, your entire argument was once again flawed.

I think you should stop digging, but each to their own.

 

[Laminar Flow]

Ergo, your entire argument was once again flawed.

I think you should stop digging, but each to their own.

A boat is more than a single part; try looking at the bigger (stability) picture. I'll be happy to follow scientific evidence and the properly applied physics and math of the experts, even though I understand that, in the UK, expert opinion is not much in fashion these days.

 

[eddystone]

One aspect of contemporary cruising boat design I do not understand is the cut away forefoot and flat sectioned forward profile which in my limited experience of such boats seems to make them a bit twitchy?

 

[geem]

Worth a read Practical Sailor Takes a Look at Trends in Modern Boat Design - Practical Sailor

 

[Laminar Flow]

Worth a read Practical Sailor Takes a Look at Trends in Modern Boat Design - Practical Sailor

Thank you for posting, and also comprehensively answers Eddystone's question.

 

[Concerto]

Worth a read Practical Sailor Takes a Look at Trends in Modern Boat Design - Practical Sailor

A very interesting article, along with the attatchments, that explains what I dislike about modern wedge shaped wide beam boats.

The strange thing is I feel mast height has been reduced to some older boats. My Fulmar (designed as a cruiser racer in 1979) with ¾ rig is berthed between a Jeaneau Sun Dance 36 (36.16 ft LOA designed 1988) and a Moody S38 (39ft LOA designed 1988) (both masthead) and my rig is between both in height. The Sun Dance 36 is about 2ft shorter and the Moody S38 is about 18 inches taller. Both have substantially larger volume hulls with higher freeboard.

I cannot find the I, J, P, E sail dimensions for each design. The Fulmar has a 465 sq ft sail plan, the Sun Dance 575 sq ft and the Moody S38 722 sq ft. As none of these are the wedge shape I think the Sun Odyssey 361 closely matches the Sun Dance 36 at 35.89 ft LOA and wedge shape despite being a 2008 design. The 361 has a 685 sq ft sail plan, which is 19.1% more area than the Sun Dance 36. This seems to confirm sail plans are increasing in area, as per the Practical Sailor article.

The authors certainly show how inclining the hull shape changes the shape of the hull in the water. I know all boat designs are a compromise, but I feel the wide wedge shape hull is a step too far for a cruising boat to be comfortable to sail and quiet at anchor. Too much emphasis is given to the interior design at the expense of comfort under sail.

 

[flaming]

Worth a read Practical Sailor Takes a Look at Trends in Modern Boat Design - Practical Sailor

I mostly lost interest when they said

Many recent and current cruising boats, if suitably fitted out with racing sails and the hardware and software to tweak them, could put up an impressive show on the race course.

Which is, as has been discussed many times here, laughably untrue. There has never, ever been as big a gap between racing and cruising designs. I can't think of a cruising design offered for sale now that would be a success on a race course. Even the Pogo type boats have struggled in race mode in anything other than downwind point to point racing.

Other than that, that article reads exactly as I expected it to. "A bunch of sailors used to sailing older boats go sailing on designs that are quite different but don't adapt their sailing technique and yet are mysteriously surprised when these very different designs don't behave in the same way as their beloved old boats do."

It is absolutely 100% true that designs that are narrower, deeper, with longer keels, are (generally) more directionally stable. But if your boat is really rounding up under full sail in 15 knots of breeze, your trim is badly wrong. No boat is actually that bad. And the trim tips you would use for an older boat are not the same for a newer design. Which for some reason comes as a surprise to people.

It's absolutely telling that the authors of that article, when they talk about what they did to stop the rounding up talk only about the main, about flattening and dropping the traveller. Stands to reason, they clearly learnt to sail in the days of masthead genoas and fairly hi cut clews. Trim tips for that sort of boat when racing were to hang on to the biggest jib you possibly could, strap it in hard and then use the main as a trim tab to try and keep the rudder at about 5 degrees weather helm. Try doing than on a modern boat, even a modern race boat and you'll heel far too much, be slow and spin out a lot.
A modern rig, with a high aspect jib with a low clew, develops a lot more load in the leach of the jib, and is a lot more sensitive to car position. If you're sailing along and every gust is causing you to round up, drop your car back a couple of inches. Bet that solves the issue. First time I had that explained to me was by a sailmaker from North, out racing with us for the day on the old Elan. Completely transformed how we set the boat up in gusty conditions, and rounding up became a thing of the past. And I've taken that same tip and used it on modern cruising boats on charter etc. If your helm is loading up, step 1 is car back a tiny amount. Helm becomes light and off you go again, and normally faster as well.

So not really an issue of the hull, actually an issue of the rig, which the hull is not disguising in the same way as hulls of the past might have done.

 

[geem]

I mostly lost interest when they said


Which is, as has been discussed many times here, laughably untrue. There has never, ever been as big a gap between racing and cruising designs. I can't think of a cruising design offered for sale now that would be a success on a race course. Even the Pogo type boats have struggled in race mode in anything other than downwind point to point racing.

Other than that, that article reads exactly as I expected it to. "A bunch of sailors used to sailing older boats go sailing on designs that are quite different but don't adapt their sailing technique and yet are mysteriously surprised when these very different designs don't behave in the same way as their beloved old boats do."

It is absolutely 100% true that designs that are narrower, deeper, with longer keels, are (generally) more directionally stable. But if your boat is really rounding up under full sail in 15 knots of breeze, your trim is badly wrong. No boat is actually that bad. And the trim tips you would use for an older boat are not the same for a newer design. Which for some reason comes as a surprise to people.

It's absolutely telling that the authors of that article, when they talk about what they did to stop the rounding up talk only about the main, about flattening and dropping the traveller. Stands to reason, they clearly learnt to sail in the days of masthead genoas and fairly hi cut clews. Trim tips for that sort of boat when racing were to hang on to the biggest jib you possibly could, strap it in hard and then use the main as a trim tab to try and keep the rudder at about 5 degrees weather helm. Try doing than on a modern boat, even a modern race boat and you'll heel far too much, be slow and spin out a lot.
A modern rig, with a high aspect jib with a low clew, develops a lot more load in the leach of the jib, and is a lot more sensitive to car position. If you're sailing along and every gust is causing you to round up, drop your car back a couple of inches. Bet that solves the issue. First time I had that explained to me was by a sailmaker from North, out racing with us for the day on the old Elan. Completely transformed how we set the boat up in gusty conditions, and rounding up became a thing of the past. And I've taken that same tip and used it on modern cruising boats on charter etc. If your helm is loading up, step 1 is car back a tiny amount. Helm becomes light and off you go again, and normally faster as well.

So not really an issue of the hull, actually an issue of the rig, which the hull is not disguising in the same way as hulls of the past might have done.

For a start these guys aren't racing. They are out for a sail. If 2” of traveller adjustment make so much difference then there is something seriously wrong with these boats. Most cruisers do not admust their sails to that level of finesse.
I think I tend to go with the guys from Practical sailor who explain very well the issues with modern hull design. I just cant accept thet 2” of traveller adjustment is the answer to why these modern hulls are a handful in benign conditions. Since most cruisers arent racers and many cruisers we see seem to be very poor at setting sails, on the basis of what you say then there is no hope for the poor sailor who cant trim sails if he has a modern hull design.

 

[flaming]

For a start these guys aren't racing. They are out for a sail. If 2” of traveller adjustment make so much difference then there is something seriously wrong with these boats. Most cruisers do not admust their sails to that level of finesse.
I think I tend to go with the guys from Practical sailor who explain very well the issues with modern hull design. I just cant accept thet 2” of traveller adjustment is the answer to why these modern hulls are a handful in benign conditions. Since most cruisers arent racers and many cruisers we see seem to be very poor at setting sails, on the basis of what you say then there is no hope for the poor sailor who cant trim sails if he has a modern hull design.

If that was the basis of their argument, then you would have a point. But it wasn't. They were bemoaning the new boats for not behaving like the old boats, without stopping to consider if the way they were sailing the boat was in any way influencing the boat's behaviour.
As regards the 2" dropping of the car (not traveller, jib car) back. To be honest I wouldn't expect most cruisers to have bothered bringing it forward in the light. It's just that the rounding up is not being caused by the main, as they will have been conditioned to expect, so they're reacting with traveller and main sheet and getting annoyed when the boat doesn't behave as their old one did, when it would probably be prevented in the first place with jib car. (Although obviously a wildly over trimmed main, or one that is far too big for the conditions, will also cause broaching.)

Approach is not constant moving of cars, it's more " if my boat is rounding up all the time, bring the jib car back a bit. If I'm not bothered about top speed in the light, leave it back. Problem solved, go back to reading book."

 

[geem]

If the boat is that sensitive to sail trim its the wrong boat for cruising. End of

 

[flaming]

If the boat is that sensitive to sail trim its the wrong boat for cruising. End of

You're missing the point. It's not all that sensitive to trim, it's just that the trim actions they talk about are all mainsail related because that's what they grew up doing to stop rounding up. And then bemoaning the fact they aren't working as they would in the older boats. When in fact they're not realising that with a modern RIG (not hull) an awful lot of the rounding up pressure is being generated by the leach of the jib being too straight. It's not necessarily more sensitive per say, it's simply sensitive to different inputs.

Which is completely logical. Even in that article they go to great lengths to point out the difference in the hull forms, the change in wetted surface area etc. But they fail the final step, thinking about the change to how the rig works, and how that interacts. And they fail to ask the question "in what way does this different boat shape and rig type mean that we sailors should adopt different approaches to sailing it". Instead they just blame the boat for not reacting in the same way as the older boats.

 

[geem]

Most cruisers wouldn't know if the leach was too straight!! The point is you can get the trim terribly wrong on an older seaworthy design and it still behaves well. Get it wrong on a modern design and they behave terribly. That is the point. The hull is so sensitive to poor sail trim that as a package its not a great solution for the average sailor

 

[Lightwave395]

If the boat is that sensitive to sail trim its the wrong boat for cruising. End of

Don't agree with your sweeping statement at all, although I'm not a 'liveaboard' which may be more what you mean by 'cruising'.

Each to his own, I cruise in an ex-race boat, it's very comfortable for two of us to spend three months on at a time, it's fast, safe and as an ex racer I enjoy tweaking and sailing a nicely setup, well balanced and quick boat. I don't see that and cruising as mutually exclusive - whatever floats your boat....

 

[Concerto]

It's absolutely telling that the authors of that article, when they talk about what they did to stop the rounding up talk only about the main, about flattening and dropping the traveller. Stands to reason, they clearly learnt to sail in the days of masthead genoas and fairly hi cut clews. Trim tips for that sort of boat when racing were to hang on to the biggest jib you possibly could, strap it in hard and then use the main as a trim tab to try and keep the rudder at about 5 degrees weather helm. Try doing than on a modern boat, even a modern race boat and you'll heel far too much, be slow and spin out a lot.

A modern rig, with a high aspect jib with a low clew, develops a lot more load in the leach of the jib, and is a lot more sensitive to car position. If you're sailing along and every gust is causing you to round up, drop your car back a couple of inches. Bet that solves the issue. First time I had that explained to me was by a sailmaker from North, out racing with us for the day on the old Elan. Completely transformed how we set the boat up in gusty conditions, and rounding up became a thing of the past. And I've taken that same tip and used it on modern cruising boats on charter etc. If your helm is loading up, step 1 is car back a tiny amount. Helm becomes light and off you go again, and normally faster as well.

So not really an issue of the hull, actually an issue of the rig, which the hull is not disguising in the same way as hulls of the past might have done.

Most cruising yachts of all ages now have furling headsails, these never set as well as a purpose made sail that is never rolled. Many modern cruising yachts have furling mainsails, which certainly perform far worse than a non furling mainsail. The high aspect foresail may be in need of genoa car moving aft in certain conditions but involves someone moving forward to do this as they are not rope controlled or they are on a self tacking track with no agjustment once set. Sorry Flaming but your comments might be right, but do not apply to most cruising sailors. Every weekend you will see cruising sailors either using just the foresail or mainsail to poodle along. If the boat was sailed better with both sails and have them set closer to how they should look, their boat would sail faster. To many it is not about speed but comfort under sail. I try and sail my Fulmar singlehanded in the 90% to 95% range of what could be achieved by a full racing crew, unfortunately I see many cruising yachts in the 50% to 75% range. They tell me I have a quick boat, but they also use their engines a lot more than me. I am very well aware of how to set up my rig using a Loos guage and many cruising sailors comment that it is too tight and could deform the boat. These are generally the people who buy the modern wedged designed hulls. They never seem to learn how to improve their performance by understanding sail handling, rig setting, tidal navigation or hull shape. Just watch people at a boat show, as soon as they get onboard, they head down below. If they spend any time in the cockpit, it is due to too many down below. They never walk along the decks to the bow, if fact at one show I was not allowed to walk to the mast on one boat that was sitting in a cradle. Most people who buy modern cruisers have little knowledge of performance and to be quite frank could not care about it as long as they eventually arrive at their intended destination.

In another thread on a Hunter 40, one wife wanted the boat for the accomodation but hated the way it sailed and they quickly sold it to buy a HR. This says a lot about how poorly conceived the modern hull design has become in understanding what the cruising sailor wants - accomodation first, followed by the latest fashion in yacht design with twin wheels, twin rudders, drop down transoms, hull windows, wired for every conceivable electronic device, etc. To me a well designed boat should be easy to sail so that it has a wide range to get good perfomance, be stable and comfortable in rough weather, lie to anchor without "sailing" around the anchorage and with no slap under the transom, easy to moor in a marina and get ashore, be strong enough to take the ground if something goes wrong (drying out alongside a wall or running aground at speed), etc. Most of these factors seem to be ignored in the current crop of modern cruisers.

 

[flaming]

Most cruisers wouldn't know if the leach was too straight!! The point is you can get the trim terribly wrong on an older seaworthy design and it still behaves well. Get it wrong on a modern design and they behave terribly. That is the point. The hull is so sensitive to poor sail trim that as a package its not a great solution for the average sailor

They don't have to know the leach is too straight. They just have to know that moving the car back is something to try if they keep spinning out.
But they don't because Authors of articles like that one don't bother to find that out and tell them they just tell them that this is the trade off for the nice accommodation that they like.

Yes, designs with full keels and low CoG masthead rigs are more forgiving to bad trim. Nobody is disputing that. But, to my mind, the cruising public are being done a disservice by articles like that practical sailor one that just harp on about how great things used to be, without actually asking what techniques might be well suited to getting the most out of the boats that most of the readers are actually sailing.

 

[flaming]

Most cruising yachts of all ages now have furling headsails, these never set as well as a purpose made sail that is never rolled. Many modern cruising yachts have furling mainsails, which certainly perform far worse than a non furling mainsail. The high aspect foresail may be in need of genoa car moving aft in certain conditions but involves someone moving forward to do this as they are not rope controlled or they are on a self tacking track with no agjustment once set.

Now that is my major complaint about modern manufacturers. In their race to sell for the lowest price they have somehow managed to convince a lot of people that towable cars etc are "racy" and not suitable for a cruising boat. Which is a total nonsense.

Sorry Flaming but your comments might be right, but do not apply to most cruising sailors. Every weekend you will see cruising sailors either using just the foresail or mainsail to poodle along. If the boat was sailed better with both sails and have them set closer to how they should look, their boat would sail faster. To many it is not about speed but comfort under sail. I try and sail my Fulmar singlehanded in the 90% to 95% range of what could be achieved by a full racing crew, unfortunately I see many cruising yachts in the 50% to 75% range. They tell me I have a quick boat, but they also use their engines a lot more than me. I am very well aware of how to set up my rig using a Loos guage and many cruising sailors comment that it is too tight and could deform the boat. These are generally the people who buy the modern wedged designed hulls. They never seem to learn how to improve their performance by understanding sail handling, rig setting, tidal navigation or hull shape. Just watch people at a boat show, as soon as they get onboard, they head down below. If they spend any time in the cockpit, it is due to too many down below. They never walk along the decks to the bow, if fact at one show I was not allowed to walk to the mast on one boat that was sitting in a cradle. Most people who buy modern cruisers have little knowledge of performance and to be quite frank could not care about it as long as they eventually arrive at their intended destination.

No argument at all with your description of modern cruising sailors. But not sure how that's an argument in this debate? If they're only pootling along under headsail at circa 50% of the boat's potential, then they are not going to be spinning out like the boat testers in the Practical sailor article...

In another thread on a Hunter 40, one wife wanted the boat for the accomodation but hated the way it sailed and they quickly sold it to buy a HR. This says a lot about how poorly conceived the modern hull design has become in understanding what the cruising sailor wants - accomodation first, followed by the latest fashion in yacht design with twin wheels, twin rudders, drop down transoms, hull windows, wired for every conceivable electronic device, etc. To me a well designed boat should be easy to sail so that it has a wide range to get good perfomance, be stable and comfortable in rough weather, lie to anchor without "sailing" around the anchorage and with no slap under the transom, easy to moor in a marina and get ashore, be strong enough to take the ground if something goes wrong (drying out alongside a wall or running aground at speed), etc. Most of these factors seem to be ignored in the current crop of modern cruisers.

Nobody is claiming that there is no such thing as a bad boat... And that Hunter does sound like one...

As for your cruising boat requirements. It's a sensible list, but it won't be universal. I, for example, wouldn't be so bothered about transom slap or ability to take the ground, but would want decent performance and a really good comfortable helming position. Which is often hideously overlooked.