the W Magic Numbers

a quick summary of Wayfarer "magic" numbers

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the mainsail and mast by the numbers:

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MAST:
* rake: 23’ 5” to 23’6” - boom should hang level (parallel to water) with no tension on mainsheet
(23’2” in survival conditions: boom angles down towards transom)
* spreaders: length (mast wall to tip): 20 to 20½”
angle (tip to tip) medium wind: 38” (less in light, more in blow)

MAINSHEET:
* thickness: needs to be only about 7 mm (¼”) which will run very nicely through Harken 082 (bullet) blocks
* length: should only be about one foot longer than length needed to allow boom to touch shroud on a run while bridle is at its flattest setting - anything more is waste and creates tangles with other ropes (e.g. spi halyard)

VANG:
Should be a powerful system that can easily be adjusted by the helm while sitting out on either
side of the boat. Ours is about 40:1. 12:1 is the minimum needed for efficient adjustment while racing!

OUTHAUL:
Should be reasonably easy to adjust while racing - ours is 4:1 and controls run to both sides.
Basic setting is for maximum foot depth - progressively less foot depth as boat becomes overpowered or backwinding is a problem. Flattest setting is used on a run and in drifters or survival.

HALYARD: 3/32” wire looped over a halyard rack, Holt-Allen HA345.

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the genoa by the numbers

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on SHADES
* jib halyard is 1/8” wire looped over the hook of a magic box
* the jib is (almost always) sheeted to a point
- 20.5” from the middle of the centreboard slot
- 3.5” from the forward edge of the centre thwart
* rig tension, which comes from the jib halyard, should usually be just enough to remove visible slack from lee shroud while sailing close-hauled
NOTE: An even more functional approach to rig tension, i.e. jib halyard tension 99% of the time, is to crank on excessive tension and then do the one really important test:
Sail close-hauled and see if your sailing groove is wide enough.
If there is not enough (fore/aft!) curve in your jib entry, your sailing groove becomes too narrow, i.e. the number of steering degrees between luff and stall becomes so minute that your tickers will indicate luff one second and stall the next with very little change of course. What is happening in this case, is that instead of flowing along both sides of the curved surface of your sail, the wind is alternating between bouncing off the windward and leeward sides of your sail entry (which is disastrous to your performance!)
A jib luff entry becomes too flat because the halyard is too tight.
What we therefore do is overtension the jib halyard for the conditions, test our upwind ticker performance and then decrease halyard tension until the tickers settle down - i.e. we are in the right groove (enough curve in the luff entry) for the conditions.
If at any time during the race, I find that it is getting uncomfortably hard to steer by the tickers, I immediately ask my crew to decrease halyard tension a bit.
Another case of: When in doubt, let it out!
Of course it is also true that the more rounded your entry, the lower you will be able to point.
Thus you only want the entry as rounded as necessary to feel comfortable with your tickers! .....
more magic tuning numbers as posted on UKWA web site in May 2001
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