Let´s be practical. Are we in the right way?

[Vega]

Originally Posted by condor

The 473 is more fun to sail than the B57. The B57 is an event and a prodigous amount of fiberglass to throw around. I have day sailed them both and the 473 has a higher fun potential. I have single handed them both and the 473 is much more fun in lighter airs. In heavy stuff, the center cockpit and close poximity of the winches and traveleler on the B 57 are a plus.

It makes sense

Originally Posted by condor

As I said a well found 35 can go to Bermuda and it will be an adventure. …But, that said, if you met us both at the dock upon arrival in St. Georges, let me tell you, my crew wil be rested, shaved, washed, relaxed and the boat will look orderly and ready to go again.

Most crews coming off a 35 foot boat will be tired, beat up and cranky. The boat will be a mess and everyone will be ready for a good night's sleep and meal out.

Well, I guess that the concept of adventure can vary widely with each person. For me an adventure is what that 50-year-old French sailor achieved, some months ago, I mean, a non stop circumnavigation by the 3 capes, on a 20 year old 34ft Jeanneau .

I agree with you about the sailors on the small boat being more tired (if they get rough weather), but I very much doubt they would be cranky. I believe they would feel what you normally feel when you enter a port after a difficult passage: A sense of accomplishment and joy for a well done job. I believe, that short of a hurricane that is a pleasure you will not feel in your boat .

Originally Posted by condor

Little expereince in any boat is not a great idea. At the bottom line, it is the expereince of the captain and the crew that always makes the difference. That includes not going offshore ina poorly prepared and maintaineed boat.

That said, my only point about which I am niether strident nor apologetic is simply that a modern big production boat is a safe fast way to get around the ocean.

This point does fly a bit in the face of an older school of salty thought that only certain boats have the pedigree to venture over the horizon. About that I do not agree. I also feel that size helps.

I could not agree more.

[Vega]

Originally Posted by Antonio Alcalá

So, what are you really telling me Vega? You mean I did the right choice with my 473 or not? ...
Please read my attachments and let me know your opinion about my 473 ( calculations by Guillermo Gefaell). I always think that everyday everyboday don´t stop to learn something.

Hum… I am not the kind of guy that will say to you that a Halberg-Rassy or a really heavy displacement, or the opposite, a lighter boat than yours is better or worse for you. If well designed, and most of them are, all types have advantages and disadvantages and only you can know what you value most and therefore be able to find the right boat. I don’t know enough of you as a sailor and a cruiser to give you sound advice.

But I can tell you that the Stix of the boat is not 51 but 48 and the AVS is not 126, but 119, considering MinSC.

That is not important because the boat has a good Stix and the AVS is normal for this kind of boat. The hull design is very modern (Now jeanneau, Bavaria and others are following) and I believe it is a very seaworthy boat.

I believe that a draft of 1.7 to that boat is rather limiting on the pointing ability of the boat. A draft of around 2.2 would give it a better upwind performance.

I would prefer the mainsail car on the cockpit and not over the cabin, but that is hard to get on a pure production cruising boat. I hope you have not a furling mainsail.

I don’t like very much the interior Set-up, neither the furniture .

Over all it seems to me a very good cruising boat with emphasis on the sailing performance and seaworthiness.

António, test sail the Amel that you have posted on your site. If you find that boat delightful, than you have the wrong boat. If you find the boat nice but boring, probably you have made the right choice for the price you have paid. And if it is the case, then you can change your dream, replacing the Amel by the Cigale .

[DanishBagger]

Well, then you guys are using size as a metophor for production boats, good quality and what else you have used. Or perhaps we could say, that you have used "size" in the same way as someone describing a symptom and calling the symptom the cause for the disease.

The thing is, when Condor uses the parameter "size", one ought to be able to deduct, that he is actually talking _size_. Especially since he is saying, that a boat in a size 35ft, will be hard work doing passages in. So your explanation is, that he is really meaning a non-production, awful sailing, poorly built one-off?

I did write something about "all things being equal" – and as such that is a parameter one should use, when directly comparing boats and generalising on size alone. Otherwise, it'll be hard making convincing sweeping statements such as "Only big boats are comfortable – A 35 footer is too small to be comfortable – People on 35 footers are always way more tired than people on my size (57ft) boat" and so forth and so on.

Further, I am not doubting quality in any way, and purely from the looks of his boat, I'm pretty sure he is right, that the B57 is a great passagemaker. But again, to deduct from that, that production boats are great passagemakers is just as stupid as someone saying production boats cannot be great. There are many production boats I don't consider to be anything more than glorified day sailers (i.e. bigger than mine - which would include berths, head and a galley), but just as unfit for a crossing to Iceland. And some of those are made by some of the worlds greatest designers too – but unfortunately "passagemaking" wasn't really part of the design brief.

[DanishBagger]

Sorry, my above was a response that should have come in after Vega on page two - I didn't see there were three pages.

[Guillermo]

Back from Barcelona, something very quick before going out for some more boating:

- Size matters. That's why STIX favours size ('Basic' STIX formula is just a function of length, and the collection of additional factors just correct this initial figure up or down).
I've crossed the strait between Key West and Cuba on a 23 footer in a force 7 northeaster against the Gulf current for a whole night. Not a delightful experience, I'd say. Also I've beaten to winward many times when racing in the 'Costa de la Vela' (an infamous 3 miles run between Vigo and Pontevedra's rias) in force 5-6 northwesteries against an ebbing tide, on a variety of boats ranging from 23 to 50 ft, both light and heavy. I can tell doing it in the smallest ones was miserable, indeed.

- I agree with Mike John's statement on material having little to see in the performance of a cruising boat when over certain lengths. You can get as low as practical D/L ratios using waterever material. SA/D and SA/WS ratios are the relevant ratios to compare, for boats with similar D/L one.

- Antonio boat's STIX is probaly bigger than 51, as per the data and GZ curve he provided, and could be even as high as 56, depending on the downflooding angle (info on this is missing), wich is pretty remarkable for this kind of boat.

- I'll try to work out numbers on the 30 footer Antonio suggested later this weekend.

Cheers.

P.S.
Let me post here what is still a widely accepted categorization for boats, depending on their D/L ratio:

BOAT TYPE ---- D/L RATIO
Light racing multihull 40-50
Ultra light ocean racer 60-100
Very light ocean racer 100-150
Light cruiser/racer 150-200
Light cruising auxiliary 200-250
Average cruising auxiliary 250-300
Heavy cruising auxiliary 300-350
Very heavy cruising auxiliary 350-400

[DanishBagger]

Yup, all things being equal - size is what to go by (and go for). It just bugs me, that he's making sweeping statements about people not being able to be rested in a smaller boat, or that a 35 footer (which, btw, is much bigger than the specific 23 footer you're talking about) cannot be seakindly (essentially saying that 35 foot or less is per definition boats with bad seakeeping. That is poor bollocks, no matter what stix-numbers you care to drag out.
I'm willing to go as far as talking "tendencies" in that direction, and that it is possible to conclude that, if all other things being equal, then size is surely the thing to aim for. The Stix number might be a good indicator, but it will never be an end-all answer. It is still just an indicator, or a symptom, if you like.
(I sound more pissed off than I am – I'm in a good mood, so cheers! :-))

[Antonio Alcalá]

Nice to see you again Guillermo!!!!

I think you can contribute to goes up the scientific level in this forum and of course in this post . Let´s see fellows... Lets´talk about real situations under sailing beeing us the protagonist. This may be help to explain some about the design and therefore the stability of modern non custom boats.

For example: one and a half month ago I was sailing close to Isla de Alboran, it was dark night, no moon, windforce 6-7 my 473 run over the water till 8 knts at 140 º AWA with the third reef and 8 turns of genoa roller. The boat was really fast but the height of the waves went up to 12 feet. We had crossed sea sometimes. In one of that waves, it broke over all the lenght of tha 473 ( 12 feet maybe more) and the clinometer moved on from 15 º till exactly 45º ( or maybe more but not much more). The boat did regain in 2 seconds the 15 º. It was I repeat a 12 feet wave crashing on the beam.

Guillermo, Vega or anybody, I ask you:

1.- This fast reaction of the 473 was due to the great number of stix ( I hallucinate when Guillermo thinks that can goes up to 56)

2.- With a 2 meter wave heighter, Would the 473 running into danger of a capsize or maybe not

3.- What´s your opinion about if I was incresead my speed taking only two reefs with 6 genoa roller turns till let´s think....10-11 knots

Waiting your surely clever, brilliant and experienced responses

A.

Best winds

[Vega]

Originally Posted by DanishBagger

I guess my point is, that seakeeping isn't really a parallel to size: You cannot deduct that a bigger boat is more comfortable based on size alone.

Originally Posted by Vega

No, it can be a very badly designed sailboat. But that is a thing that is very rare among production boats and almost inexistent among big production boats (they are designed by the world's best architects). If it is not the case, yes, size matters in what regards comfort. I am not talking about the quality of life inside the boat on the marina (for that I prefer quality to size) but to the way the boat moves through the waves. And regarding this, the difference between a 35ft and a 60ft is huge.

There seems to be some confusion. When referring to big, Condor was referring to his own boat, a boat with almost a 60ft. I have said that “the difference between a 35ft and a 60ft boat is huge”. And when I have said: “No, it can be a very badly designed sailboat. But that is a thing that is very rare among production boats and almost inexistent among big production boats (they are designed by the world's best architects). If it is not the case, yes, size matters in what regards comfort”, I am clearly talking of 54-60ft big production boats, boats about the same size of condor's boat.

I believe you did not understand what I have said , or you really are saying this about any of the big production 54-60ft cruisers on the market? :

Originally Posted by DanishBagger

There are many production boats I don't consider to be anything more than glorified day sailers … but just as unfit for a crossing to Iceland. And some of those are made by some of the worlds greatest designers too – but unfortunately "passagemaking" wasn't really part of the design brief.

[Vega]

Originally Posted by Guillermo

- I agree with Mike John's statement on material having little to see in the performance of a cruising boat when over certain lengths.

Yes, of course. But of what lengths are you talking about?

Originally Posted by Guillermo

Antonio boat's STIX is probaly bigger than 51, as per the data and GZ curve he provided, and could be even as high as 56, depending on the downflooding angle (info on this is missing), wich is pretty remarkable for this kind of boat.

Even 48 STIX is a very good number for a 47ft sailing boat.
I agree that if this is the curve you are talking about (picture), probably the STIX is bigger than 48…but I am confused, because Beneteau had previously released as stability information: 51 STIX and 119 AVS.

Antonio, who has provided you with that Stability curve? (picture).

[Antonio Alcalá]

Vega, I did ask for it to Beneteau and they sent to me, and some data and pictures too, the rest did it Guillermo

A.

[Vega]

Originally Posted by MikeJohns

This issue of load and performance is worth exploring further

There is displacement mode and semi-displacement mode, I think a lot of these lighter designs with flatter sections can operate in the semi arena when operating lightship in conditions that suit. But even a realistic minimal cruising load will see performance comparable with the heavy cruisers depending on the factors I mentioned before.
Once the light-weights get really loaded their performance suffers considerably since they are not a hull-form that suits a loaded condition wrt performance. …

…. yes if you want them for that one attribute-speed then you are going to be strict on accumulated weight, but this very weight may be sensibly required and not accumulated eclectic collections of junk .

Consider a basic cruising load.
Ground tackle, prudent seamanship dictates carrying 2 backup anchors with at least some chain, each of a size to hold the boat in adverse conditions, in coral areas an all chain rode is required. Then an outboard motor and its fuel, a dinghy, life raft, wind generator and or solar panels ,maybe a radar? SSB radio and antenna tuner. Laptop computer, wet weather gear, some spare sails. Reasonable tool set.

I have said:

Originally Posted by Vega

«

About hull speed, the one for my boat is 7.35k. I can guarantee that downwind, on those typical trade winds (after all we have the Portuguese trade winds along our shore ), my boat, with 25 to 35k of wind sails well over hull speed (from 8 to well over 9K). And I am not talking of surfing. Last year I have made a leg with 70 Nm averaging 8k (and on the first hour and a half I didn’t make more than 6.5k. And I am not talking of a boat in minimum sailing condition, but on a boat equipped for cruising one and a half months and to make thousands of miles. Of course, this doesn’t mean that the boat is near Max load. I don’t like to travel with lots of dead weight around .

"On a boat equipped for cruising one and a half months and this means on my 36ft boat ":

Ground tackle, 2 backup anchors, all chain rode on the main (50m, more some meters for the main backup) an outboard motor and its fuel, a dinghy, life raft, a radar, Laptop computer, wet weather gear, some spare sails, Reasonable tool set.

That seems remarkably close to your list .

I also have a Navtex but I have not a SBS radio and antenna. Most of the speedy cruisers (I did not want to say modern) have changed that for a small and very light satellite phone with a link to the laptop, for receiving e-mails with meteorological information.
I don’t have a wind generator. I have instead an engine with two alternators. As the boat, with the help of a big Geenaker can sail with very light winds, and the engine is a small 29hp, the 150L of diesel will last a long time (I only need of about 4 liters a day for recharging the batteries).

I even have a light aluminium gas barbecue, not to talk about the Bimini and other sun protections.

So, I think you are exaggerating .

Originally Posted by MikeJohns

I think that when you trade Comfort factor for speed (particularly from the viewpoint of women and children) that your boat becomes less of a home and more of a vehicle.

Well, there are different kinds of sailors….and different kinds of families.

My older daughter, even if nowadays has very little time to sail with the family (University and social life ) only had fun when the boat was going really fast, my 14 year old son considers sailing a drag…except when the boat sails well over 8k. That’s when he shows up and takes the wheel. And my wife really appreciates everything that shortens the trip and considers that any small discomfort during the voyage is of no significance, considering the hours (or days) that will be gained.

Yes, definitively, the boat is a vehicle while sailing and a home while at anchor or at the marina.

Yes I believe that the issue of load, performance and cruising offshore is worth exploring further.

You say that:

Originally Posted by MikeJohns

All the designers are sitting on a detailed weights and moments calcs for their vessel. It would be simplicity itself for them to add this equipment for "loaded" stability and yet what they call heavy-ship is I suspect nothing more than full tanks, they don't even say whether they counted people and where they put them, have they been counted as movable ballast and put in the most advantageous position ?

I don’t know about other boat manufactures, but on the cockpit of my Bavaria there is a visible tag, marked CE (so I believe all the modern boats have one) that says the boat can carry a max of 8 people and luggage in a certain amount of weight. The max load condition is not referred anywhere, that information would be meaningless to most consumers, but obviously the Max sailing weight is the addition of the light boat weight, plus tankage and the weight that is on that tag.

About this:

Originally Posted by MikeJohns

However if you sail relatively short fast legs and have good shelter in between and the opportunity to regularly re-provision then the performance cruiser can well suit the time-limited cruiser and provide a vigorous enjoyable experience.
....Reasonably expected load is the Achilles-heel of lighter performance cruisers and the smaller the light weight gets the more significant the effect

Of course, if you cruise with 8 people inside my boat (I wouldn’t) the provisions needed to all those people plus the added weight of the bodies would have the effect you describe. The boat would sail badly and would have little autonomy.

I would say that on a modern production 36ft cruiser, only on the charter market they will sail with 8 people, and I am sure they would have little sailing experience.

A boat like this is comfortable doing coastal cruising with a family of 2 adults and 2 or 3 kids. For two couples it is already too much. That means not only the interior space, but also the storage weight. If you use the boat offshore, and that doesn’t mean necessarily to cross oceans (If I don’t sell the boat I will probably sail to Madeira and perhaps Azores), the boat will be comfortable for only two people and if you want to live aboard permanently, I would say that the boat would be comfortable for a single one.

Of course, this is what is comfortable for me and other sailors would think otherwise, but this model (and many similar ones) have circumnavigated without any reported problems.

But if you sail in an old 36ft, like the Vancouver (to quote one still in production), you can carry more load, but you will have a lot less interior space and a lot less cockpit space, so in the end, probably the boat could carry 2 couples and the provisions, at a lesser speed, but I would not be one of them. Too cramped for my taste, even for a couple.

Not to mention that for the price of the heavier boat you could buy a modern production 42ft sailboat, that would take the two couples plus the needed load, even faster (comparing with the modern 36ft) and in a lesser cramped way.

Cheers

[DanishBagger]

Originally Posted by Vega

There seems to be some confusion. When referring to big, Condor was referring to his own boat, a boat with almost a 60ft.

No, he wasn't – he was extrapolating his experiences with his particular production boat to any and all production boats. As were you.

I have said that “the difference between a 35ft and a 60ft boat is huge”. And when I have said: “No, it can be a very badly designed sailboat. But that is a thing that is very rare among production boats and almost inexistent among big production boats (they are designed by the world's best architects).

Yes, extrapolating. But still, you're missing the point. Because I say it's bollocks to claim that any 35 ft is uncomfortable as a general rule, doesn't mean that I somehow claim that production boats sucks. That is a strawman argument. And I have not said such a thing. I have gone into this discussion because of the stupidity of sweeping statements.

If it is not the case, yes, size matters in what regards comfort”[/color], I am clearly talking of 54-60ft big production boats, boats about the same size of condor's boat.

Sure.

I believe you did not understand what I have said , or you really are saying this about any of the big production 54-60ft cruisers on the market? :

No, not at all. As I have said and explained numerous times, I am bitching about sweeping statements that a 35 footer cannot be comfortable, and the just as idiotic statement, that because the b57 is a good passage maker, and the b57 is a production boat, thus all production boats must be good passage makers. It's an Erasmus Montanus-argument (a Ludvig Holberg play): Mother cannot fly, a rock cannot fly, ergo mother is a rock.

Edit: You quoted me for saying something about glorified daysailers – this was a jab at the statement, that production boats - which apparently all are designed by the best designers of the world - had to be good passage makers – because they were designed by the best designers of the world. But, you left that portion out. The worlds best designers doesn't design a great passage maker, if they're designing a day sailer and add enough berths to be chartered. In this line of thought, boats are also designed to be spacious (above all else), and because they're used as charter boats, they're production boats, but that is not a guarantee that they will make good passage makers, nor be comfortable in harsh weather.

If you'd like, I could link to Condors posts in this thread, but it's just as easy if click on his profile name and do it yourself.

[Guillermo]

Originally Posted by Vega

...I don’t know about other boat manufactures, but on the cockpit of my Bavaria there is a visible tag, marked CE (so I believe all the modern boats have one) that says the boat can carry a max of 8 people and luggage in a certain amount of weight. The max load condition is not referred anywhere, that information would be meaningless to most consumers, but obviously the Max sailing weight is the addition of the light boat weight, plus tankage and the weight that is on that tag.

That tag is mandatory for all boats commercialized in the EU nowadays. The number stated after the 'luggage' symbol in the tag is the maximum recommended load to be carried by the boat, under the CE categorization, including all items (people, luggage, fuel, water, stores, etc).

Cheers.

[Guillermo]

Originally Posted by Antonio Alcalá

....one and a half month ago I was sailing close to Isla de Alboran, it was dark night, no moon, windforce 6-7 my 473 run over the water till 8 knts at 140 º AWA with the third reef and 8 turns of genoa roller. The boat was really fast but the height of the waves went up to 12 feet. We had crossed sea sometimes. In one of that waves, it broke over all the lenght of tha 473 ( 12 feet maybe more) and the clinometer moved on from 15 º till exactly 45º ( or maybe more but not much more). The boat did regain in 2 seconds the 15 º. It was I repeat a 12 feet wave crashing on the beam.
....

Inertia plays a major role in the heeling motion of a boat when hit by a wave. The larger it is (i.e, larger displacement or larger gyradius), the smaller should be the change in heeling motion (heeling acceleration and heel angle) for a given heeling moment imposed by the action of breaking waves. The rolling or impact energy transferred to the boat is inversely proportional to her inertia.

No matter how heavy/light or wide/narrow a boat is, she'll not be able to withstand the impact of a beam breaking wave being over 55% of its LOA or over 1.5 times its B (depending on authors), but a more 'inertial' boat will have a better chance of surviving smaller waves than a less inertial one.

Your BO 473, being relatively light and seemingly with no specially big gyradius for her size, is relatively more prone to get deeply rolled when hit by a beam wave than a heavier or higher gyradius boat of the same size.

Gyradius has a bigger importance than displacement to diminish the capsize probability. You could increase your boat's gyradius by means of a deeper keel concentrating weight as low as possible. But, as said, you should check structural matters first with the manufacturer.

The roll moment of inertia increases more quickly with size (because of the increasing of gyradius) than with displacement, so that's why size matters, as I said before in another post.

Cheers.

[Antonio Alcalá]

I understand Guillermo... then should I calm down if I tell you my draught is exactly 2.14 mts? measured by a judge of the RFEV, it is not 1.70 like the model you kindly calculated to me, neither 2.10 mts as standard draught of 473 model..

Then I have 4 questions more:

1.- Is there any variation in your calculations after this 2.14 mts and 3300 kgs of ballast with 11500 kg at minimum load ?

2.- Was it a noble reaction of my boat hitting by a 12 feet wave, regaining the heeling angle in not more 2 seconds?

3.- Why did you say that my boat could have a STIX of 56 if only score 26.22 in the motion comfort ratio? Has it much little or that to see the motion comfort with the STIX or not necessarily?

4.-What exactly does mean this in the 473:

Knockdown Recovery Factor (FKR) 1.371
Inversion Recovery Factor (FIR) 1.071
Dynamic Stability Factor (FDS) 1.261

As they are the advantages and as the disadvantages of these calculations on the sailing form, and how can I improve them if I had to do?


Best winds Guillermo