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pondmonkey View Drop Down
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Posts: 2202 		Post Options Post Options   Quote pondmonkey Quote  Post ReplyReply Direct Link To This Post Topic: Wiki Sail by GRF
    Posted: 28 Mar 13 at 1:41pm
I can't see it being very useful, I'd much rather see the real stats of how many x are actively racing at my club and the clubs around me. I'm willing to change clubs to get class racing in a 'better boat', however that information is rarely available.
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alstorer View Drop Down
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Posts: 2899 		Post Options Post Options   Quote alstorer Quote  Post ReplyReply Direct Link To This Post Posted: 28 Mar 13 at 2:32pm
I think you've hit the nail on the head. Outside of development classes, with new designs it isn't really about building a faster boat. For pure speed but cheap we'd be kiteboarding on the coast, windsurfing inland.
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Posts: 3011 		Post Options Post Options   Quote RS400atC Quote  Post ReplyReply Direct Link To This Post Posted: 28 Mar 13 at 3:15pm
Originally posted by iGRF

.....
So I'll ask you the same question regarding the Laser. if it were split in half, halfway up the side and an inch or two added, would it make it faster in your opinion?


The bit in the water would be the same shape, apart from when the bow hits a wave.
At which point, a boat like the laser would have less drag with more freeboard, as it wouldn't be pushing the gunwhale through the water so much.
The flip side is, with more freeboard, you have more air drag, all of the time up wind.
Also in some waves, more buoyancy will lift the bow more on each wave. That can be good, riding over waves instead of smacking into them, or not so good, too much pitching motion.

Too little volume, negligible freeboard, minisail, can't sit out and keep the boat flat without every ripple hitting the helm.
Too much freeboard, GP14, drag factor of a bingo hall.

Volume added by more length is good in most conditions.
Volume from added beam is ok above the working waterline, slow if it's below the waterline except possibly when planing fast.
Volume that adds weight is almost always going to be bad.
But a shallow hull like a minisail needs to be built quite heavy to be strong enough to resist the rig loads etc.
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Andymac View Drop Down
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Posts: 852 		Post Options Post Options   Quote Andymac Quote  Post ReplyReply Direct Link To This Post Posted: 29 Mar 13 at 9:17pm
OK, here is a link which might just put iGRF's mind to rest (or then again, will it spawn many more abstract thoughts?).
If you don't get it first time, there are many more links to other similar scenarios.
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2547 View Drop Down
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Posts: 1151 		Post Options Post Options   Quote 2547 Quote  Post ReplyReply Direct Link To This Post Posted: 30 Mar 13 at 9:20am
Originally posted by Andymac

OK, here is a link which might just put iGRF's mind to rest (or then again, will it spawn many more abstract thoughts?).
If you don't get it first time, there are many more links to other similar scenarios.

Error, you are falling into the trap that iGRF is constrained by the laws of physics. He operates in his world where those laws can be bent to suit his arguments. 
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pondmonkey View Drop Down
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Posts: 2202 		Post Options Post Options   Quote pondmonkey Quote  Post ReplyReply Direct Link To This Post Posted: 30 Mar 13 at 9:35am
Here's one for you Graeme, yesterday windsurfing in an offshore easterly at Daymer.  For those not familiar with the Geography, it's a cornish river estuary, so for this example assume cross wind to river flow.  It's marginal planing breeze, enough to water start in the gusts, 7.7 NP sail (so relatively big) and riding a 113L board (neutral buoyancy once the rigs on it and I'm neoprened-up like a sex pest)

Sailing into the the tide (flood) I could get planing on stb.  Sailing with the tide I couldn't... weird or just goofy/regular riding issues?


Edited by pondmonkey - 30 Mar 13 at 9:38am
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Medway Maniac View Drop Down
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Posts: 2788 		Post Options Post Options   Quote Medway Maniac Quote  Post ReplyReply Direct Link To This Post Posted: 30 Mar 13 at 10:32am
If the true wind was really square to the current, then the apparent wind would have been more forward on one tack than the other, meaning the sail force vector would have been more sideways and the resulting thrust less.
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fab100 View Drop Down
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Posts: 1005 		Post Options Post Options   Quote fab100 Quote  Post ReplyReply Direct Link To This Post Posted: 30 Mar 13 at 10:36am
Originally posted by Medway Maniac

If the true wind was really square to the current, then the apparent wind would have been more forward on one tack than the other, meaning the sail force vector would have been more sideways and the resulting thrust less.

Beat me to it, but, yup, apparent wind effect of tide
Great book for Club Sailors here
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fab100 View Drop Down
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Posts: 1005 		Post Options Post Options   Quote fab100 Quote  Post ReplyReply Direct Link To This Post Posted: 30 Mar 13 at 10:47am
Originally posted by fab100

Originally posted by Medway Maniac

If the true wind was really square to the current, then the apparent wind would have been more forward on one tack than the other, meaning the sail force vector would have been more sideways and the resulting thrust less.

Beat me to it, but, yup, apparent wind effect of tide


Oh hang on. This is the GRF wiki

So there has to be a far more complex, lunatic reason: the salinity of the wave-surface will be 
greater going one way than the other as the sea hits the less salty river stream, adding buoyancy to the board? And, as the earth is not perfectly spherical, there will be less gravity so you will weigh less too?

Must be that, the apparent wind stuff is widely recognised by us silly, closed-minded, brain-washed, experienced sailors who have made decades of effort to learn stuff, so must be misguided nonsense, under the rules of the master
Great book for Club Sailors here
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iGRF View Drop Down
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Posts: 6499 		Post Options Post Options   Quote iGRF Quote  Post ReplyReply Direct Link To This Post Posted: 30 Mar 13 at 1:10pm
Except it's not apparent wind is it?

The cumulative effect of the tide and real wind increase the power, apparent wind is only created in any force once the board is planing.. So the power of the true wind dare I even say it.. (Knowing full well this is a Jimbo troll) Classic Lee Bow tide effect.

Plus he's probably goofy on port (he's goofy on every other point of walking, running, riding....

Edited by iGRF - 30 Mar 13 at 1:12pm
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