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Old 02-04-2014
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Re: Interesting Sailboats

I find this discussion about chines very interesting. And it seems to me that –once again- there is not a single answer.

On one hand there’s the Hunter 40’ concept, a boat that certainly is not designed to sail well but especially to be comfortable under power and at anchor. These chines will also add a significant amount of volume in the aft cabins, which also perfectly fits the specific program of this boat.

On the other hand there’s the “open” formula racing yachts, designed to be as fast as possible within the limits of a box rule and that nowadays all have sharp chines.

Sailing one of these, albeit a cruising version, I can confirm Paulo’ analysis that a well designed, beamy and chined hull gives a huge form stability, which also permits to save on ballast and thus on weight. Especially when they also fit a very deep keel (3m on our Pogo 12.50 and therefore swinging).

I think we can all agree that this concept boosts performance because the low weight, reduced heel and very flat aft sections allow to plane early, even starting from a close reach.

And I confirm once again that this does not impair upwind performance. We are as fast –I’d rather say as slow- as almost any other as long as we don’t try to point. In other words: the VMG is as good -or as bad- as it gets with almost any other design. Except in very choppy conditions, because of wave drag, as Paulo explained in a much earlier post (I certainly hope you didn’t delete that one, Paulo!).
So if I quite dislike sailing upwind, it’s not because we’re slower but only because we know how much more fun we would have when bearing down, even a little.

But even in the context of non-planing Bénéteaus, Sun Odysseas, Hanses etc. I feel chines also can give added value, other than extra space in the aft cabins.

First, the ability to fit twin rudders further apart and therefore more efficiently, because of the much flatter aft section. I hate them when maneuvering because there’s almost no prop wash, but when sailing they give much better control and also demand less effort from the autopilot, especially downwind. This is certainly an important feature from an easy cruising point of view.

Second, as soon as the heel allows the sharp chines to “bite”, the point of lateral resistance moves aft and strongly reduces the weather helm caused by heeling. This once again results in better control, requiring less effort.

Third, these boats indeed don’t like to be heeled “over the chine” and will clearly let you know by slowing down, making leeway and –if you really didn’t take the message- rounding up very, very slowly. As my 470 dinghy coach teached me a long time ago: “sail the boat under the mast”. In other words: avoid excessive heel, reef early. Once again a useful feature for easy cruising.

So if we agree that most comfort cruisers don’t like to sail close hauled in choppy seas any more than I do, I feel well designed chined hulls do have more significant advantages than only “fashion”, added interior volume or less rolling under power or at anchor.

Best regards,

Eric
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