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Name	JB
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Sail Fair.

2018-12-28 13:12:23

2018 SYC rankings

Board » Sailonline Yacht Club

Good afternoon all.

Probably I'm missing sometning but, I don't understand why my first seven 2018 40' Series results were discarded from my SYC results.

Thank you.

João/psail
Sail Fair.
2018-12-28 10:00:16

40’ Series hiatus.

Board » Sailonline Race Committee » Races

Good morning all.

I’ve read the SRC annual report about the 40’ Series and it’s sad to know this SOL championship won’t turn in 2019.
I understand and also agree with SRC exposed arguments. Pity that a phew conditioned the remaining majority.

One possible way for overcoming the main issue, if not, the only one - the boats overuse/abuse from some skippers - is to make the Series races with pre-fixed boats for all, turning the Series to a OD championship with #4 - #5 40 footers to be used.
But you loose part of the game.

Other suggestion, independently of the Series future format (OD or multiple choices), is to upgrade the Series with faster boats, instead of “artificially” downgrading the faster ones (notice: one was already available in the SOL marina for the 2018 Series).

From my part I’ve trying since a while to bring the Melges 40 Polar but till now without success.
So, if anyone out there can give an hand on this I’ll be very thankful.

Thank you.

João/psail
Sail Fair.
2018-12-25 17:14:22

Re: qtVlm thread

Board » Technical Support

Hi Philippe and all.
Good afternoon.

Well, the settings I’ve been using a long time (since they were available) are the same, so I don’t have any induced distortion on comparing results generated with different settings.

Those settings have proved to give results in all kind of WFs and with different boat Polars, being also more relevant with the faster boats, as you easily understand and as per example I sent you recently.

Correct, the lower the Time Step (TS) used for calculating the Isochrones, the bigger will be number of potential WPTs. That’s the price for getting precision.

The first point you mention misses rationality.
We all know that ANY GRIB file won’t be exactly what you are going to sail IRL. Under that argument - yours - I ask why do we make routings?

I totally agree with your second point and part of the third. For that I can give you one plausible answer for people not using TS = 5 minutes: I takes a lot of time to get a result, not because is less precise.

In relation to fourth point, previously I gave you a suggestion: bring back the old "cutter", which I now reiterate.

If it doesn’t have anything to do with the used TS, what’s the problem for implementing it again?

My Dear Friend have also
a Merry Xmas

João/psail
Sail Fair.
2018-12-25 11:49:39

Re: qtVlm thread

Board » Technical Support

In past years we saw a quick evolution not only on weather routing software but also on sidekicks aiding tools.
One of the best weather routing programs used around the corner is qTVlm. Since the very first versions it has been upgraded in a good rhythm bringing also a plethora of innovations, sometimes using info and suggestions gathered from the community.

Anyhow, one qT aspect that has been roller coasting is the Optimizing/Simplifying algorithm processes applied to the calculated routing WPTs.

It is very simple to verify that in spite of using the “Optimum Simplify” process first, and "Optimize" after (applied only once or several times), normally we won’t get the best ETA - even before any trimming operation on the fixed calculated WPTs, the ones in “red” color generated around land/rocks/barriers and on the remaining "green" movable ones.

The cause for this is identified. Is a direct consequence of the used decimating algorithm implemented in qT for the “Simplify”/ “Optimum” processes.

In recent versions - 2018 - this issue was aggravated as the decimating operation during the “Simplify” process stopped being uniformly applied along the routed path, leaving us to the somehow paradox of having more remaining WPTs in the end of the route, precisely where the predictability of the WFs are worse, which is a contra sense.

There are ways to overcome this issue but, again with another contra sense, as you have to spend more time rehabilitating an over decimated routed path by adding new WPTs.

Every WPT over decimated is a less one degree of freedom in the generated curve, giving here the main reason for qT going in opposite direction of the optimum ETA.

Sincerely hope that qT responsible persons take once for all this issue and, at least bring back the “old” decimating algorithm, the uniform “cutter”.

João/psail
Sail Fair.
2018-12-25 08:55:38

Re: GGR race final position.

Board » Sailonline Race Committee

Good morning SRC and all,

Thank you for your reply &
Merry Xmas.

João/psail

Sail Fair.
2018-12-21 21:48:37

GGR race final position.

Board » Sailonline Race Committee

Dear SRC and all,

Good night.

Only now saw the final leaderboard for this race and, as expected I've suffered a time penalty accordingly to the race rules.

In fact, I've departed from Hobart before time - didn't respect the 90 minutes stopover. It's a fact.

Anyhow, if you look to the attached pictures you'll understand better what happened and following actions from psail.

After recognizing my mistake I immediately imposed a self-penalty, stopping the boat for more than 90 minutes.

So the late SRC action doubles the previous token on due time, i.e., the self imposed penalty psail made.

For the mentioned reasons I kindly ask SRC to review psail final race position.

Thank you SRC.

João/psail

Sail Fair.
2018-12-21 21:35:50

Re: qtVlm thread

Board » Technical Support

maitai said @ 2018-12-14 15:07:13:

No such problem here, what version are you using on which platform?

@João/psail what other problems ?

Replied today to Philippe.
Latter I'll give further details.

João/psail
Sail Fair.
2018-12-13 13:20:32

Re: qtVlm thread

Board » Technical Support

Hi all.

Andrew, if memory doesn't fail, the related problem came on the qT 5.8.2 version, hence the main reason for stop upgrading qT since 5.8.1 (there are other reasons).

João/psail
Sail Fair.
2018-11-28 12:45:13

Cookson 50 Polar data

Board » Technical Discussion

Hi all.

Some time without coming here.

Let’s see if the SOL community can bring some help on this subject.
Please, I need a Cookson 50 Polar.

The ones (#4) published on the link:

http://jieter.github.io/orc-data/site/

are limited as they stop at TWS = 20 Kts.

The other reference I’ve found to the Cookson 50 Polar was on

https://www.duo.uio.no/bitstream/handle/10852/12589/master_nils.pdf?sequence=1

but has a poor graphic representation.

So, if you have or know a location where I can extract one, pls give info.

Thank you.

João/psail
Sail Fair.
2018-06-25 06:48:09

Re: qtVlm thread

Board » Technical Support

Viva Philippe

Good morning.

Thank you for info.
Yes, it works as the former "B" command.

Big Hug
João/psail
Sail Fair.

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