Zezo forum:

Post by Ultimate Victory | 2020-11-19 | 14:27:59

We used to have these kind of discussion in the past, so I'm opening one. Which group will be best position to catch the low pressure in the south ?
Does the corridor between the St Helen High and the 40th will be open ?
How far does the west group will have to go south ?

All the best to all
.UV

9 Comments

Post by YourMomSA | 2020-11-19 | 14:43:04

It seems so wildly variable that I've been choosing to focus on southbound progress rather than chasing the "cut the corner to the East!", "Wait, no, go to Brazil!" routings. Eventually, it'll settle on something more stable, and whoever is fortunate enough to be placed correctly for that will be happiest.

I think the variability is actually a North/South positioning of the winds from the West in the forecast, rather than the entire forecast being chaos. When it's projected to be far enough North for a downwind path to open up along the ice line, the router wants us to go to Brazil and run downwind in that. When it's projected to be under the ice limit, the router wants to find a meandering path through the messy winds that remain above the ice limit. Which we'll get... hell if I know.

The most important thing is... once the leaders get into a well-defined weather system with winds from the West that's actually above the ice limit... You need to be in the same system as the leaders. As long as that is achieved, it doesn't really matter who's leading. Everyone in the same system will most likely converge later at the front of the system (unless it's travelling too fast).

Post by bikeinside | 2020-11-19 | 18:44:59

So you stick to the east side of the West group, to have room to play with if you need to go more west to catch the downwind path?

Post by milonga2 | 2020-11-19 | 22:17:56

Looks like there are a lot of us to the east of the western group ! Let's be radical, but not too much ! lol

Post by YourMomSA | 2020-11-20 | 01:44:52

The western group is enormous. Theoretically, it'll contain everyone who has chosen to follow Zezo's routing the entire way.

My route isn't really about positioning relative to the Western group. It's really just about me having decided to keep pushing South and "figure the rest out later". The forecast for the South Atlantic has been changing with every update, so I decided i'd rather go south than chase the changes.

Post by BooBill | 2020-11-20 | 04:11:17

Wait a minute. I thought you guys in the east group were following the router?

Seriously, coming out of Theta the router indicated the route the east group took if you were navigating to 45S. That looked dodgy to me and conflicted with my general strategy of following the wind west looking for a point around mid-Atlantic to head south, crossing the doldrums far enough west to avoid the light stuff, far enough east to have good angle when we hit the SE trades.

Since then the router has vacillated on each and every update between; a) what I call the circle route down the west side to pick up the western side of the St. Helena high, or b) a diagonal route that ran a transition ridge to a low that was forecast to split the high in half, offering a short cut through. Not only has the GFS driven Zezo route flipped back and forth of each update, on each occasion ECMWF indicated the opposite. That's from my perspective near the west side of the west group. I'm sure the east group has seen a more consistent diagonal path through the high.

Anyways, as in the best line from the Cannonball Run, "What's a behind me, no matters." (symbolically throws rearview mirror overboard)

We are nearing a point where a commitment to a) or b) will have to be made. Being so far west, I'm obviously hoping for a)

The risk with the circle has been that the low you hope to pick up doesn't extend above the ice limit. The risk with the diagonal is that the bridge doesn't reach the other side of the high.

My only advice is, don't follow me. I have no clue which way I'm goig to go.

Post by YourMomSA | 2020-11-20 | 05:24:28

Interesting. I wasn't routing to the 45S destination, because at that time, the 16-day routing couldn't reach that point. I was routing to a self-selected destination in the South Atlantic, and for that destination, Zezo was wanting me to go West. I wanted a more aggressive line, remembering a boat that stayed East and crushed the Atlantic four years ago, so I altered my destination to a spot south of Cap Verde, and forced the routing that way for a few days.

I'm guessing a lot of the West group was routing to the FdN waypoint when exiting Theta.

Post by milonga2 | 2020-11-20 | 07:14:19

Thanks for the analysis, it's nice to see that not only the beginners like me go through perpetual dilemma. My main advantage is that I will always be behind you guys (no full pack and no experience) so I can see 5 or 6 hours in front of me the consequences of your choices :) . But I suppose even this delay is not enough. So if I follow you guys it will be a bet anyway.

Today the routing shows southern stronger winds well over the ice limit, looks good to me !

Post by zezo | 2020-11-20 | 12:44:01

Sit back, relax and watch the show ;-)

I've sailed this course virtually more than 20 times. First time you learn to avoid the beginners mistakes (like going down along the African coast)

Then it's always different, and always a lottery to some extent.

With the current forecast it looks like the first 1000 boats will arrive at Agulhas within 10 minutes, so the race will be decided later. Usually that's after Cape Horn on the way back, the same area in front of us, but it's even less predictable when sailing north.

In the end the winner may be determined by the knowledge of game quirks and perfect execution of the smallest details, not by the strategic choices.

Post by Bemerech | 2020-11-20 | 17:19:59

Hi,
Interesting!!

Strangely enough the router told me, with hesitation, to go South-West just after Theta (I was ranked ~430 at that time) -- Quentin Vlamynck was taking this route and I knew he is *excellent* at routing, so I decided to follow, after much hesitation.
I was routing to Cape of Good Hope (not 30E though).
When the forecast became unstable I decided to get 2/3rd of the way between the East group (I call it the South group... YourMomSA's) and the West group (Vlamynck's), 'cause the winds could bring me easily to the West if needed.

... which eventually occured. I'm 32�W now and compared routing hints it is a very good place. We'll see how things develop. Anyway, I expect (fingers crossed) to be in the same meteorological system as the leaders :o)