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Definition of Planing
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    Posted: 01 Mar 19 at 7:33pm
Rule 42.3c states Except on a beat to windward, when surfing (rapidly accelerating down the front of a wave) or planing is possible, the boat’s crew may pull in any sail in order to initiate surfing or planing, but each sail may be pulled in only once for each wave or gust of wind.

“Surfing” is defined in the rule, but “planing” is not, nor is it defined in the definitions section of the rules. For that matter neither is “gust”.

I read the interpretations of Rule 42 on the WS website, but can’t see anything that defines planing (or gust), and I don’t believe either is as straightforward to define as may first appear.

The WS interpretations do say that planing need not be successfully achieved, but it does have to be possible (and if you fail to get planing after more than two attempts are likely to have broken the rules).

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Daniel Holman View Drop Down
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Posts: 997 		Post Options Post Options   Quote Daniel Holman Quote  Post ReplyReply Direct Link To This Post Posted: 01 Mar 19 at 8:46pm
Planing is when a substantial part of displacement is supported by dynamic lift rather than bouyancy. Fn = 1 i.e. 12kts for a 14ft dinghy is where true planing can start. But for a canoe or catamaran which won't create lift it won't be planing.
12kts is pretty fast for most 14ft dinghies.
I guess surfing is the more likely excuse for some kinetics, which is defined as presumably acceleration on a wave? How big is a wave etc etc.

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Posts: 3400 		Post Options Post Options   Quote Sam.Spoons Quote  Post ReplyReply Direct Link To This Post Posted: 01 Mar 19 at 8:49pm
So cat sailors can't pump to get planing  LOL
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Post Options Post Options   Quote Guests Quote  Post ReplyReply Direct Link To This Post Posted: 01 Mar 19 at 9:10pm
Originally posted by Daniel Holman

Planing is when a substantial part of displacement is supported by dynamic lift rather than bouyancy. Fn = 1 i.e. 12kts for a 14ft dinghy is where true planing can start. But for a canoe or catamaran which won't create lift it won't be planing.
12kts is pretty fast for most 14ft dinghies.
I guess surfing is the more likely excuse for some kinetics, which is defined as presumably acceleration on a wave? How big is a wave etc etc.

Yes, but “substantial” isn’t very precise and linking it to Fn is not a definition, more a rule of thumb or convenience. Loads of Laser and RS200sailors would claim to be planing at much lower speeds than that.
And yes, what constitutes a wave...
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Posts: 8956 		Post Options Post Options   Quote Rupert Quote  Post ReplyReply Direct Link To This Post Posted: 01 Mar 19 at 9:45pm
Surely the idea here is that the boat can break displacement wave forms and go faster than waterline length would normally allow? Hull shapes, weight and rig design will all affect a boat's ability to successfully go faster than displacement speed. Long thin hills don't create the same wave forms, so yes, I'd say that cats shouldn't be allowed to pump. Bet they do anyway.
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Post Options Post Options   Quote Guests Quote  Post ReplyReply Direct Link To This Post Posted: 02 Mar 19 at 7:52am
So planing is sailing at any speed greater than “allowed” by waterline length, unless it’s long and thin? Pretty vague still, for the basis of enforcing a rule. Presumably the allowed speed would be Fn = 0.4 (where wavelength equals hull length), but that isn’t a hard barrier to speed in displacement mode, many dinghies can go faster than this upwind.

And anyway, why should you only be allowed to sheet in once per gust if it gets you planing (however defined)? Seems discriminatory against boats that would still accelerate without planing.
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Posts: 8956 		Post Options Post Options   Quote Rupert Quote  Post ReplyReply Direct Link To This Post Posted: 02 Mar 19 at 9:06pm
Why should it be allowed at all, do you mean? Sounds like adding a paddle stroke to me.
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Post Options Post Options   Quote Guests Quote  Post ReplyReply Direct Link To This Post Posted: 02 Mar 19 at 9:56pm
Why shouldn’t everyone be allowed to sheet once per gust, regardless of whether you get planing? Seems sensible if no definition if planing exists, and why should only some boats be allowed to (try to) benefit?
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Posts: 997 		Post Options Post Options   Quote Daniel Holman Quote  Post ReplyReply Direct Link To This Post Posted: 02 Mar 19 at 10:14pm
If sailing properly, one should be adjusting sheets to every change in wind strength and direction / steering input / waver pertubation. When does an adjustment become a "pump" or some other kinetic grey area.
I like kinetics its bloody skillful, and think that those like Paul Henderson who would seek to regulate it out entirely would remove a major part of the art.
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Posts: 8956 		Post Options Post Options   Quote Rupert Quote  Post ReplyReply Direct Link To This Post Posted: 03 Mar 19 at 7:41am
Sheet adjustments and body movements are designed to make the most of conditions as they change, and as you say, they are (or will be if you concentrate) constant. Pumping is creating power by human means.

Much wiser minds than mine have failed to spot the difference. It can be impossible to tell even when sailing oneself whether a particular movement was making the most of conditions or creating them.

Sometimes it is bleeding obvious, though! But I don't really think we should stop promoting increasing speed as wave conditions allow by not allowing limited body or mainsheet movement. Sailing is supposed to be fun, after all.
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