boat brands - prejudice or reality

[potentillaCO32]

I was on a modern HR the other day. No chart table is not a feature I'd like on any boat irrespective of age or manufacturer.

Maybe charts are on their way out. Did it have a nav station for chartplotter/tablet etc

 

[Egret]

Another question - if we want a boat that is going to take a bit of rough and tumble, maybe a long way away from a repair yard, do we really want a foam or balsa sandwich hull, or would we rather have solid GRP

 

[Tranona]

Another question - if we want a boat that is going to take a bit of rough and tumble, maybe a long way away from a repair yard, do we really want a foam or balsa sandwich hull, or would we rather have solid GRP

What difference does it make? Why do you think a cored hull is any more of a problem than a solid one? The vast majority of modern boat have cored hulls and there does not seem to be an epidemic of problems with using them or getting them repaired if damaged.

If it makes you feel better have an old boat with a solid GRP hull or even a steel, ferro or wood. .

 

[Tranona]

As an engineer familiar with thermofluid having spent a chunk of my career working in that field, I can honestly say that's not correct.
You are correct that chines added above the waterline are useful for adding reserve buoyancy. My 32 year hard dinghy has such features. It does add reserve buoyancy but also plenty of drag when the chines are immersed. Anything that increases surface area as chines does increases drag, particularly in light winds.
Interestingly, more volume is achieved by a hemispeircal shapes with less surface area than any chine. A round bilge boat has less drag than a flat one with chines.

Well I would stack David Thomas and all the other designers who use chines successfully against you any day of the week. We are not talking about old dinghies but substantial cruising boats where the designers have worked out that carefully positioned chines at the stern improve performance, reduce drag and increase buoyancy and allow more hull volume.

 

[Tranona]

Are you sure they are not mentioned? The website says “The new hull design with wider transom and lifted soft chines suits the X4³ MkII very well. The additional form stability is quite noticeable, as is the considerably less wake and turbulence of the heeled transom travelling through the water.”
X4³ MkII |.

You are doing it again - quoting facts straight from the builder. If I could be bothered I could probably dig out Maurice Griffiths comments on the redesign of the GH31 with double soft chines which made exactly the same point over 50 years ago.

 

[Laminar Flow]

On chine hulls:
Chined hulls have a minimum 5% higher resistance than round bilge forms. This was established by tank testing. Rounding off the chine, R= 0.008 DWL, significantly improves resistance. (Konstruktion u. Bau von Yachten, Scharping, page 96 and continued)

Yes, I too have owned a Griffiths chined design. My current, round bilged tub would absolutely sail circles around it (see avatar).

The success of the early Van de Stadt hard chine designs had nothing to do the chine. It was because they were significantly lighter than the competition.

The well known IMOCA designer Juan Kouyoumdijan explains the advent of contemporary chine design:
"In order to reduce the extraordinary beam the wide arc of the bilge would dictate, we simply cut off the excess." There, bingo, you got your chine!
When asked about the adoption of it in contemporary AWB design, he laughed.

I'm sure I'll be accused again of ignoring empirical data by someone who took a walk through the marina, counting boats with chines and, consequently, conclude they must contribute brilliantly to a boat's sailing ability and for the obvious reason that people bought these boats and that there is a market for ones that, at the least, look fast.
By the same measure, if a few years ago, counting the number of fins and rocket extrusions on cars in a parking lot would have led to the obvious conclusion that these accoutrements must greatly improve aero dynamics and allow automobiles to fly.

 

[potentillaCO32]

Well I would stack David Thomas and all the other designers who use chines successfully against you any day of the week. We are not talking about old dinghies but substantial cruising boats where the designers have worked out that carefully positioned chines at the stern improve performance, reduce drag and increase buoyancy and allow more hull volume.

Very true.

Despite refitting and loving an old boat I recognise advances in hull design/manufacture and enjoy sailing light modern fast boats.

I think what laminar flow forgets is that the chine allows the boat to lean onto a flat surface and continue planing at greater wind angles.

Indeed we imported a range a few years ago. Very little can beat the feeling of sailing a wide flatish bottomed boat at well above traditional hull speed.
I remember one sail where we averaged over 10 knots from Lowestoft to burnham.

The reintoduction of hard chines and wide sterns has created a lot of fast exciting boats.

 

[Baggywrinkle]

When asked about the adoption of it in contemporary AWB design, he laughed.

Claiming that he "laughed" at chines on production boats is a bit disingenuous .... I assume you are referencing this interview below .......what he actually said was this ...

Q: But how to explain the advantages of chines, when actually used properly in production boats? ‘In these boats,’ he says,

A: ‘you are allowed to end up with any hull shape you want, you can choose any beam at the back of the boat. There are no specific rules. That freedom allows you to exploit transom shapes that reduce dynamic drag as a function of heel and speed. So if you say what is the advantage – well, I don’t think there is an advantage per se, like “OK, we have a chine, therefore you have an advantage”. It’s more like, if you optimise the hull with complete freedom, no rules, you will most likely end up with a hull that has a chine at a very specific spot. So, like I said, the chine is a consequence, it’s an output.’

Q: OK, but to be even more specific: the advantage of this hull shape, that for one reason or another ends up with chines – is it mostly present on broad sailing angles, maybe even planing? Or is it good upwind as well?

A: ‘It can actually be very good upwind,’ Juan explains. ‘Particularly for boats with a symmetrical keel in the middle, like a regular production boat.
‘When the boat heels the chine helps in balancing the boat. It’s good for safety as well. On a boat with a wide transom and a single rudder, the rudder has to be very far forward on the hull to stay in the water when the boat is heeled. That reduces steering moment, and to overcome that it’s necessary to make the rudder bigger. Which gives you more drag. But even now, with the rudder moved forward on the hull, you will find it very difficult to press the boat hard, because the boat will lose balance with a lot of heel.
‘Putting the chine in the water helps balance the boat back. It’s almost like having an extra rudder in the water. When the chine is submerged the boat will have a tendency to bear away a little more. That makes it possible to load the sails harder, add some more power to the boat and take advantage of its form stability. Thus the chine can help take pressure off the rudder.
‘The same thing actually applies on broader angles – if the boat is fast enough. Fast boats will always have the apparent wind pretty much forwards, and basically experience roughly the same situation, when it comes to side force and heeling.
‘On normal displacement cruising boats, that almost never exceed hull speed, the whole concept of wide sterns and chines doesn’t really have any relevance – certainly from a performance point of view. Even on lightweight, faster boats the chines have to be designed properly and located properly. Otherwise they don’t do anything. Chines can only make the boat go faster within a very specific set of circumstances, and I don’t see these circumstances appearing very often on a normal production boat.’

Effective design or fashion craze - Juan Kouyoumdjian Naval Architecture

I read that as the production boat design houses, specifically this lot ....

• Group Finot (France): Famously designed many Beneteau models.
• J&J Design (Slovenia): Extensive work for various European production builders.
• Bruce Farr / Farr Yacht Design (USA/Global): Known for performance cruisers and racers.
• Germán Frers (Argentina): Frequently designs for Nautor's Swan and Hallberg-Rassy.
• Berret-Racoupeau (France): Commonly used by Beneteau/Jeanneau.
• VPLP Design (France): Major firm for multihulls and performance monohulls.

.... get a brief from the manufacturer based on what they think they can sell, and that is a mix of performance and fashion, based on customer and yachting press feedback and the yacht manufacturers own reading of the market.

What always sells is space, be that in the cockpit or down below - generally, people aspire to a larger, more luxurious boat, same for cars, houses etc. I don't think this is in dispute, in its extreme, right up to billionaire level they are competing for the biggest and most luxurious yacht. Length has a direct impact on marina costs, so does width, but that's width at the widest part so if you carry the beam all the way to the stern then you increase liveable space without an increase in marina costs. Unsurprisingly, production boat manufacturers are exploiting this - it is especially visible in med-moor marinas.

So given that a production boat has no racing ruleset it needs to adhere to, Juan Kouyoumdijan says - "you are allowed to end up with any hull shape you want, you can choose any beam at the back of the boat."

So production manufacturers choose wide sterns for increased space in the cockpit, large swim platform, and spacious rear cabins - that won't sell to the traditionalists, but they aren't the customers, so the production boat builders don't care. It does put pressure on more traditional designs though, because once these fat bottom boats end up mainstream, and the shock has worn off, the advantages for warm-weather boating become fairly obvious.

The consequence of the choice to carry the beam as far aft as possible is a chine. Once you have a chine, it has certain effects on the boat performance, but not necessarily its speed - namely upwind performance, balancing the boat, and reducing steering moment. - source Juan Kouyoumdijan

So , I agree there are probably no performance benefits in terms of speed for a production boat, but speed is not the only measure of performance, and as Juan said, for a wide sterned boat (chosen as a market requirement), the resultant chines improve upwind performance, balance the boat, and reduce steering moment.

That's why fat-ar$ed boats have chines, it's not a fashion statement, it a consequence of having a fat ar$e, which is a consequence of wanting more liveable space.

We are also seeing- but more subtly - and increase in width forward of the beam too, in order to increase space in the forward cabin(s). Not as extreme as a scow, but it might get there - who knows.

 

[mrming]

Design trickles down from race boat hulls to production boats because a lot of the work has already been done to create a hull that works. In the late 90s / early 2000s the Figaro 1 race boat hull by Finot ended up in many Beneteau First and Oceanis models. Now we’re starting to see the scow bow being adopted in a less extreme way, pushing buoyancy (and space) forward. On the other hand, styling trickles down from super yachts, hence we see “outdoor living” style cockpits in larger production yachts, with barbecue grills and fridges in the cockpit, and even tender garages in bigger models. The increasing beam creates more space for more stuff, and the boat becomes more attractive to the kind of buyer who is walking in to buy a brand new production boat. As has been well said above, there are plenty of yards who cater to the quirkier buyer, at a price.

 

[Tranona]

On chine hulls:
Chined hulls have a minimum 5% higher resistance than round bilge forms. This was established by tank testing. Rounding off the chine, R= 0.008 DWL, significantly improves resistance. (Konstruktion u. Bau von Yachten, Scharping, page 96 and continued)

Yes, I too have owned a Griffiths chined design. My current, round bilged tub would absolutely sail circles around it (see avatar).

The success of the early Van de Stadt hard chine designs had nothing to do the chine. It was because they were significantly lighter than the competition.

The well known IMOCA designer Juan Kouyoumdijan explains the advent of contemporary chine design:
"In order to reduce the extraordinary beam the wide arc of the bilge would dictate, we simply cut off the excess." There, bingo, you got your chine!
When asked about the adoption of it in contemporary AWB design, he laughed.

I'm sure I'll be accused again of ignoring empirical data by someone who took a walk through the marina, counting boats with chines and, consequently, conclude they must contribute brilliantly to a boat's sailing ability and for the obvious reason that people bought these boats and that there is a market for ones that, at the least, look fast.
By the same measure, if a few years ago, counting the number of fins and rocket extrusions on cars in a parking lot would have led to the obvious conclusion that these accoutrements must greatly improve aero dynamics and allow automobiles to fly.

We are not talking about chined hulls against round bilge where you would indeed expect greater hull resistance with chines - particularly hard single chine.

The subject under discussion here is short chines, maybe 10% of the waterline length at the stern of an otherwise round bilge hull. The additional resistance is likely to be small to non existent as most are not hard but rounded. The reasons for chines on this type of boat has been explained by several posters and by quotes from designers/builders. Doubt anybody here (including the critics) have ever sailed or owned one of these boats, but I have read several "tests" which are unanimous in confirming they perform as claimed. Whether the "fashion" continues will depend on developments of alternatives that might be a better solution, but for now chines do what they claim with virtually no downsides or cost penalty.

BTW pointless making comparisons of sailing performance between your round bilge boat and a chined MG design - as you remarked in relation to Van de Stadt early designs the chined hull form had little to do with their success and superior performance compared with rivals.

 

[DownWest]

An aspect from way back, our single chine 27ft was measured for an RORC rating. The girth measurements suffered compared with a rounded hull, giving us an unfavourable rating. (I don't know how it works now.)

 

[potentillaCO32]

We are not talking about chined hulls against round bilge where you would indeed expect greater hull resistance with chines - particularly hard single chine.

The subject under discussion here is short chines, maybe 10% of the waterline length at the stern of an otherwise round bilge hull. The additional resistance is likely to be small to non existent as most are not hard but rounded. The reasons for chines on this type of boat has been explained by several posters and by quotes from designers/builders. Doubt anybody here (including the critics) have ever sailed or owned one of these boats, but I have read several "tests" which are unanimous in confirming they perform as claimed. Whether the "fashion" continues will depend on developments of alternatives that might be a better solution, but for now chines do what they claim with virtually no downsides or cost penalty.

BTW pointless making comparisons of sailing performance between your round bilge boat and a chined MG design - as you remarked in relation to Van de Stadt early designs the chined hull form had little to do with their success and superior performance compared with rivals.

Absolutely. And as an importer of one of the products designed by one of the designers mentioned by baggysomeone i have spoken to the designer directly. Wide flat sterns and chines are not just for accomodation. They are to raise performance away from displacement formulae and towards planing and semi planing. And it works. Anyone who has sailed a scow bowed 6.5, or something like a Pointer 30 or Safier 24 cannot help but issue a 'feck me' expletive.
I say this as a contessa 32 owner who also loves modern fast hull designs.

 

[Laminar Flow]

I think what laminar flow forgets is that the chine allows the boat to lean onto a flat surface and continue planing at greater wind angles.

There isn't a hope in hell that the proverbial AWB will plane, least not in conditions that are within the limitations of the classification parametres, don't leave brown stains in your undies or void your life insurance. Chine or not.

The SA/D ratio is a much more consequential factor when it comes to overall performance, and especially in light air.
In real world terms, other than in racing and in as much as all cruisers are displacement craft, there is no discernable difference in actual performance between modern and even rather traditional designs. There is a wealth of empirical data to back this up.

That's why fat-ar$ed boats have chines, it's not a fashion statement, it a consequence of having a fat ar$e, which is a consequence of wanting more liveable space.

Fat-ar$e syndrome is not the result of wanting more space, at least not initially, but because initial righting moment increases to the fourth power of any increase in beam. However, there are significant disadvantages associated with wide and extremely wide beam, particularly in terms of seakindliness and overall range of stability.
As the by far greatest part oft all recreational sailing is done in windspeeds of less than Bft 5 and only a statistically insignificant number of supposedly "blue water capable" yachts ever makes a "blue water passage" or even a multi day, continuous passage, the disadvantages of wide beam and light displacement combo are rarely realized.
There is a video by the German magazine "Die Yacht" on Youtube, on the comparative behaviour of wide beam boats in a seaway. The video makes it about the difference between long and short keel, but that is not the correct reason for the substantively poorer performance of the fat-ar$ed model

In der Welle: Langkieler gegen Kurzkieler.

 

[Tranona]

While trotting out this old video is useful in showing what a nice boat the HR 29 is, the Jeanneau is not only a very poor example of the type but is nothing like the boats being discussed here. The use of chines is but one development in design to improve handling in heavier weather for all the reasons discussed. In between the late 90s when that small Jeanneau was designed and now there were many other developments that improved balance and handling. For example my Farr designed Bavaria 33 exhibited none of that wild behaviour shown in the video. Several designers/builders for example (including Frers/HR) have gone down the twin rudder route. Useful to hear what Magnus Rassy has to say on the subject here forums.ybw.com/threads/hallberg-rassy-370-review.625048/

Not sure where you get the idea that only small numbers of modern boats go offshore or "bluewater" - they may be small numbers in relation to the numbers produced, but they way outnumber the "traditional" type boats. Difficult to see how it could be otherwise as few "traditional" boats have been built in the last 25 years and most at a price that makes them unaffordable. Multihulls and production boats dominate this sector and even the up market semi custom boats follow the same design trends as the boats being considered here.

 

[johnalison]

The video makes it about the difference between long and short keel, but that is not the correct reason for the substantively poorer performance of the fat-ar$ed model

My German isn't good enough to see what their conclusions were, I'm afraid. It looked to me as if the Beneteau had the easiest motion going to windward because of its finer entry and less heel, though I wasn't sure which conditions were being shown, as sometimes they had a reef and sometimes not. The sailors seemed to be fiddling with the helm in a way that I would generally discourage, especially on the HR, and this can have a marked effect on boat comfort too.

 

[Chiara’s slave]

All I can think, looking at that video is ‘you poor bastards’ This is what a proper wide boat does.

 

[doug748]

Another question - if we want a boat that is going to take a bit of rough and tumble, maybe a long way away from a repair yard, do we really want a foam or balsa sandwich hull, or would we rather have solid GRP

I think cored hulls have been abandoned for all but high performance boats, as you imply, for very good reason.
Solid GRP coachroofs and decks have a lot to commend especially when coupled with well designed inner liners.

.

 

[Chiara’s slave]

I think cored hulls have been abandoned for all but high performance boats, as you imply, for very good reason.
Solid GRP coachroofs and decks have a lot to commend especially when coupled with well designed inner liners.

.

There was me thinking cored construction was now normal.

And it is. A random lookup of a mainstream AWB builder, they say their boats have cored decks. Bavaria, btw. No reason the others won’t be similar.

 

[doug748]

Come to think of it that new Rassy is cored in the topsides. Mature technologies tend to end up in a race to the bottom.

Certainly not a feature worth paying a premium for.

.

 

[Chiara’s slave]

Come to think of it that new Rassy is cored in the topsides. Mature technologies tend to end up in a race to the bottom.

Certainly not a feature worth paying a premium for.

.

Depends whether you want to sail an old plodder, or something that feels alive, responsive and gives you excitement and pleasure. Or whether perhaps itks just getting there that matters to you. Fact is, these days both types will get you there. HR see some advantage to it, clearly.