when to gybe
Post by iconPost by Ursus Maritimus | 2017-12-18 | 22:22:22

right now (20:20 UTC), there is an imminent gybe for everyone. what is the best moment to gybe?
- just follow like a lemming zezo's 10 minute intervals?
- wait until some others gybe?
- look at when the angle to rumb line becomes the same on port and starboard?

what decision protocol does the router use here?

commenticon 9 Comments
Post by iconPost by zezo | 2017-12-18 | 22:27:39
I'm in a position that suggests gybe in an hour, so I'll wait for the next GRIB to make the jump.

In general it's better to be few minutes late than few minutes early because you never want to sail outside of optimum TWA angles.
Post by iconPost by Ursus Maritimus | 2017-12-18 | 22:34:51
why are most sailing at 140 where 141 gives 0.01 kts better vmg ?

or is it because they choose speed and hope for better vmg anyway ;)

the next grib starts loading in zezo in about an hour, right?
Post by iconPost by zezo | 2017-12-18 | 22:41:32
Because of the VMC. VMG is only good in static conditions. In a shifting wind field it can make sense sailing at 140 or 135 or 130 if places you in the right place at the right time.

The other thing is that indicated optimum might be 141, but 140 gives you exactly the same VMG. Sometimes the polars have a flat spot and the entire 140-146 range gives the same VMG, and then you optimize for minimum gybes and maximum time asleep.
Post by iconPost by Ursus Maritimus | 2017-12-18 | 22:45:43
okay, but vmg reported is vmg upwind or downwind, not vmg towards the mark.

zezo tells me to gybe right now. maybe I take a gamble, otherwise I won't get any better than 200 of all the lemmings for sure ;)
Post by iconPost by zezo | 2017-12-18 | 22:51:44
Yes, that's the VMG/VMC distinction.

It's always a gamble. In the real world you look for the gusts in the water and you look at the clouds. In the virtual world you look for the next GRIB and the difference from the previous one.

Post by iconPost by Ursus Maritimus | 2017-12-18 | 22:53:29
gybed at 20:50:53, teking the penalty like everyone has to ...

Kroosdoiker, Alina and Marinus from Zurich Yacht Club gybed even earlier!

let's wait and see what the grib brings us
Post by iconPost by Ursus Maritimus | 2017-12-18 | 23:49:38
first hour was great, from 193 (dtl 4,20) to 135 (3,54) and no nasty surprises from the grib

*happydjmike*
Post by iconPost by Skully62 | 2017-12-19 | 02:03:26
I gybed earlier as I was a few miles behind the leaders as I was headed more. You were talking about grib and also how often zezo updates can you please explain. Thanks
Post by iconPost by zezo | 2017-12-19 | 06:57:10
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