Zezo forum: Comments from a newbie to "long term" routing

Comments from a newbie to "long term" routing

Post by benji72 | 2021-01-31 | 18:10:08

Hello,

I would like to share my experience as a new user of "Zezo" and a proposal
the addition of a function that might help to take trajectory decision.

First of all, congratulations to the developers of the Zezo tool. I rarely participate in the "e-sailing" races but I did not miss an edition of the virtual Vend�e Globe. This edition was (unfortunately) special, in the sense that I could make my settings as I wanted, without the constraints of taking into account transcontinental business trips with more than 24 hours without a possible connection to the game server.

I am really satisfied with the tool which performs qualitatively very well. For the first time I managed to keep my boat throughout the race in the weather system of the first 10,000 boats group, finishing the race 6 hours 30 minutes after the winner. 4 daily connections, including 3 around the time of the day's weather file updates, the effects of the update in the middle of the night being roughly estimated, with, in particular, a conservative approach to set my trajectory near the zone of Antarctic exclusion (ZEA).

I have two points to emphasize for the less advanced users of the router.

1) I have read that GFS files are not necessarily reliable at small distance scales; however, I have noticed that the router offers trajectories passing as close as possible to the center of tropical depressions. We had two of them during the race, 'Theta' early in the race and a storm coming from Argentina between Christmas and New Years. It is better to adopt a strategy a little more conservative than what the router indicates in this case.

2) The timing of the gybes proposed along the ZEA seemed difficult to interpret. Again, it is better to adopt a more conservative strategy, taking care that the trajectory to be programmed does not risk ending on the other side of the exclusion line.

As has been said elsewhere, the virtual race was partly played on a daring option at Cape Horn. The isochrones were complex to interpret and the medium-term routing proposed a trajectory passing well East of the Falklands. How to assess the risk taken by an option that is initially daring? Would there have been a way to "get over it" if the option finally turned out to be as goodish as the routing had indicated? I have no idea about that point, maybe experienced players could explain it?

To my knowledge, the released version of the tool does not provide next isochrones resulting from 2 points that are themselves located on the same isochron. It would be particularly interesting to visualize the superposition of those 2 isochrones sectors, resulting from these 2 points, and highlight the region in which they exclude each other. Sometimes we observe isochrones with cusps, a clear sign that 2 geographically close points are in fact reached by very different trajectories. But this is not always the case, and it was not the case for the isochrones between Cape Horn and the latitude of La Plata.

Beno�t aboard "Losten"