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Hiracer · 04-10-2010, 11:50

I think it's important to compare apples to apples.

If we believe Larry's numbers, Larry's SA/D ratio when fully loaded for cruising is over 17.

Virtually all of the SA/D ratios out there are in lightship condition. We all agree that 1400 pounds of cruising payload is too light of an estimate. Personally, I use 4,000 pounds. When you add that much weight to these light boats, you are going to see their SA/D ratios tank. That's the problem with light boats. Their SA/D ratios decrease more when loaded by the same payload than similarly sized heavy boats.

So, when you add real life payloads many of the production boats out there, they are not going to have SA/Ds ratios as large as the Pardey's boat when similarly loaded. And this is why their boat outsailed so many on their trip from Vancouver to Victoria, that and sailing skills, and the fact that many recreational sailors don't even have light air sails like drifters. So I'm not the least bit surprised that Larry outsailed a bunch of stock boats. Given the numbers, I would have expected it.

The problem with most heavy boats of older design is that they start out with low SA/D ratios, and end up with even lower ratios once a cruising payload is added, such as in the case of the BCC. Larry was aware of this issue during the design phase and made sure that his rig was of healthy size. Of course, when you work directly with the designer, and then personally build the boat, you can do things like that. You can end up with a boat that surprises people.

barnakiel · 04-10-2010, 18:50

Definitely, this boat surprised you.

I, however, will wait with getting so impressed till the day I see a BCC or a Westsail outsailing a Bavaria in light airs. This far, I have not seen such a thing.

I probably have an over critical mind as to me any two boats with the same SA/D, as long as the have the same D (and how otherwise should we compare them?), will still share the same SA/D after we add any amt of load. We are not to compare an Opti with a BCC boat, are we.

My other problem might be that having a racing background I am cruising a classic (not as classic as Pardey's though) boat. So, I have outsailed many a classic design and now many a light boat outsails me ... and esp so in light winds ;-).

I do agree with you that s.c. light designs do not carry the same payload as well as the heavier boats. But this becomes only notable when they heel and their underwater shape becomes asymmetrical, which creates its own set of issues.

It is clear we do not share opinion on heavy displacement classic hulls. But this much said, if I ever see a boat like Talesin outsailing a Bavaria I will take a mental note.

Cheers,
barnie

daddle · 04-10-2010, 19:35

A good sailor in a supposedly slow boat can most often beat an average cruiser in any other boat. Especially if that supposedly slow boat has had any kind of maintenance better than average cruiser maintenance. E.g. a proper bottom, sails less than 5 yeas old, proper rigging. Easy.

Tropic Cat · 04-10-2010, 20:38

Both Mr. Perry and Mr.Kretshmer have CF accounts and log in here every now and then. Perhaps they'll join this thread?

barnakiel · 05-10-2010, 08:13

Quote:

Originally Posted by daddle

... sails less than 5 yeas old ...

Dream on.
;-)))
barnie

Hiracer · 05-10-2010, 10:22

Quote:

Originally Posted by barnakiel

I, however, will wait with getting so impressed till the day I see a BCC or a Westsail outsailing a Bavaria in light airs. This far, I have not seen such a thing.

You are putting words in my mouth. I never said a BCC or Westsail will out sail a Bavaria.

Quote:

Originally Posted by barnakiel

I do agree with you that s.c. light designs do not carry the same payload as well as the heavier boats. But this becomes only notable when they heel and their underwater shape becomes asymmetrical, which creates its own set of issues.

Pretty sure this is not a major issue. It's the change in SA/D. The difference in extra hull immersion will be minimal because both boats will have roughly similar water planes. With the similar water planes they will sink into the water similarly if loaded with the same payload.

Quote:

Originally Posted by barnakiel

It is clear we do not share opinion on heavy displacement classic hulls. But this much said, if I ever see a boat like Talesin outsailing a Bavaria I will take a mental note.

To the contrary, I agree. As I said earlier, most heavy displacement classic hulls have low SA/D ratios and are not good peformers in light air. Taleisin is an exception, largely because it's a custom design. That's the point; Taleisin is not typical among heavy displacement classic hulls.

This started out with me stating that a heavy hull is not necessarily slow in light airs, but typically is slow, not because the boat is heavy but because it's underpowered with a low SA/D ratio. If you calculate the SA/D ratios for most heavy sailboats you will see that is true. Thus, it's not the displacement that slows the boat down as much as it's being underpowered. There are heavy boats out there that moved acceptably well in light airs, but not many.

Quote:

Originally Posted by Hiracer

A boat's speed in light air is largely a function of how much power it has, specifically the SA/D ratio. After that, underwater surface area is important.

A full keel has more surface area than fin keels, which is a disadvantage in light airs, but if the boat has enough sail area it can compensate and even overcompensate for that disadvantage. This is exactly what the Pardeys do.

The only time a light boat beats a heavy boat in light airs is when (1) acceleration is important (e.g., out of tacks on a race course) AND the SA/D is the same, the latter rarely being the case. In fact, most heavy boats have lower SA/D ratios, which is largely why they are slower in light airs. It really has little to do with displacement.

At one point I thought I had you agreeing with me in concept (except I could not agree with your tangent that the BCC was similar in light air performance to the Pardey boat):

Quote:

Originally Posted by barnakiel

Yes. I understand the aero and hydro dynamics issues, but I have seen the Pardey's boat and it did not have anything out of a standard set of sails and then again the stick is a relatively short one. So, much as I share your view on SA vs. wetted area vs. speed potential, I do not see how they could do the trick with their boat.

If we assume their boat is similar to a BCC . . .

barnakiel · 05-10-2010, 16:00

Someone says now the Pardey's have another boat. Wondering what they have done with the Talesin. Who knows, maybe I still stand a chance of seeing this one sailing.

I think the single most beneficial change made to the classic (Colin Archer like) hull was when some designers (notably in Sweden and in the US) re-thought the displacement issues and started drawing the lines with long keel but much less body volume.

The difference passes unnoticed by many sailors who never see the hulls out of the water. But one look at a Westasail vs. a Baba in the boatyard explains a lot. And then some of them got the gap between the rudder and the keel fin (e.g. the Valiant).

I believe with each of these modifications the classic hull gained a lot in sailability with only a small (if at all) loss of seaworthiness and structural safety.

Give me a Valiant and I will not ask for a J.

All this just a bit of intentional late night drift ;-)

Cheers,
b.

Hiracer · 05-10-2010, 16:14

Quote:

Originally Posted by barnakiel

Someone says now the Pardey's have another boat. Wondering what they have done with the Talesin. Who knows, maybe I still stand a chance of seeing this one sailing.

IIRC, they have three boats, including Taleisin (and a small boat yard in NZ). I think their blog, previously linked in this thread, speaks to that question.

barnakiel · 05-10-2010, 16:42

I think one does need a boatyard once they own three boats ;-)

That's probably what I saw at Kawau, without realizing. But the T. boat was not around - maybe in the shed.

barnie