Facebook

Login

Support Sailonline

If you haven't already - join the SAILONLINE YACHT CLUB!

Please also consider making a donation - all amounts are greatly appreciated!

Board » General Discussion » Weather - Brain Storm

Page: Previous 1 2 3

Posted by
Zorba777


Users avatar

Posts
67
Registered at
2020-06-06 08:22:54
2020-10-01 11:28:14 - Re: Weather - Brain Storm
@dtayls @Vlbex Good comments. This is exactly what I hoped to see in this discussion. As weather models and routing software become more accurate the human factor in SOL races would become smaller and smaller. That's not what we want. I think we all enjoyed the recent Melbourne to Osaka race because we had to deal with many unexpected WX changes and a lot of position changes. High WX uncertainty = more interesting race. Compare that to the current Darwin to Perth race, where the weather has not changed at all. There is hardly any new message on the chat, people just set their DCs for the next 24 hours and nothing happens. If WX becomes more reliable then we will get more Darwin to Perth type races, an fewer races like Osaka, where we all had problems and scenario changes to deal with.
There is probably still a few years time until WX models become too good, but we can already exchange ideas on how SOL could adapt to that if needed.

I think what most of us want is a realistic simulation, not just a "who has the best routing software" type competition where all you have to do is execute the ideal route. In real life sailors have to deal with real weather differing from what the WX update forecasted. Can we mimic something like that in SOL? And if so how?

Introducing a random factor that makes the grib we play differ a bit from the official GFS (or other) weather model was suggested. Personally I am not a fan of using random factors. The reason is that the people who implement or help to run SOL behind the screens are volunteers and often participants at the same time. There would always be a suspicion that insiders have knowledge (or access) to those random factors, while normal players can not see them.

So, *IF* any "random factors" are to be used to add uncertainty (and thus stop routers from finding optimal solutions/routes) then those random factors should come from the weather itself imo. For example, as the article I linked to mentions, there will be more access to near-real time weather data (from drones and buoys) in the future. Let's say we have a race in an area using GFS data as we currently do. Every 6 hours we have a fixed map that we sail. But if there are a few buoys in the given area that put real time wind data on internet then we could use those real time data to change the weather map we use in SOL every hour or every 2 hours. That could be as simple as adjusting all wind speeds on the basis of the difference between predicted wind speed and measured wind speed for the given locations and times. That's isn't to hard on the server as it is only done once and hour. But it would add uncertainty. And we can experiment how much weight we give to the real-time data, so that routing keeps some of its use, but adapting to changes in real weather becomes important too. If we do that we will have a much more realistic simulation, because that's what IRL sailors do too. :-D

Posted by
Zorba777


Users avatar

Posts
67
Registered at
2020-06-06 08:22:54
2020-10-01 11:36:37 - Re: Weather - Brain Storm
An other way to add uncertainty is by introducing a random factor that depends on the SOLers actions. The best candidate for that would be "wind shadow" that is caused by the other boats near you in the direction where your wind is coming from. When you are sailing in "dirty wind" your boat slows down a bit. This is also the case IRL sailing. By assigning a certain performance loss % if another boat is putting me in dirty wind, we would create uncertainty and introduce the sailing tactics that are know from real races.
I think this factor should be quite small to keep it practical. Maybe 98% performance if you are in wind shadow from another boat, we would need to test what works. This would cause boats to avoid wind shadow by moving away from the optimal routes that their routers crank out.
I think this would be very interesting, but more so for the short races and sprint races. In long ocean races it should be a very small factor (or not useful at all).

--- Last Edited by Zorba777 at 2020-10-01 11:38:14 ---
Posted by
dtayls


Users avatar

Posts
30
Registered at
2014-06-23 03:34:16
2020-10-03 04:34:24 - Re: Weather - Brain Storm
I agree with you @Zorba that "random factors should come from the weather itself".

As you know I like the idea of using a different and more accurate model (perhaps ECMWF) for the underlying simulation but that might depend on gaining access to a high quality model to which most users do not have access.

Another approach might be to introduce a certain degree of randomness in to the simulation's weather model, but what should the source of this randomness be?

One option would be to choose a random mix of two or more models. This could be (a) fixed for the whole race or (b) change over time or (c) vary by lat&lon across the GRIB or (d) both meaning <x,y,t>.

If model volatility or uncertainty GRIBs were available then this could also be used to add a little to the randomness model but I suspect many would consider this to be a step too far :-)

Page: Previous 1 2 3

Please login to post a reply.

Races

Next Race: 00d 00h 00m

Current Races:

Valletta Sprint 2025


We invite you once again to this SOL classic around the Middle Sea, departing from and returning to historic Valletta. Loseley modelled on an IRL classic often sponsored by a luxury wristwatch purveyor, our c 600nm course takes us north as far as Stromboli, then west of Sicily and south to Lampedusa and back to Valletta probably via the strait between Malta and Gozo. This year we will race it all in very Meddy Dufour 40’s!
Race #1949
INFO by brainaid.de
Dufour 40 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: SYC
Race starts: Dec 20th 11:00 Registration will open soon
▶ Flash
GO TO RACE

Aeolian Cruise 2025


This is the final race of the ARCH 2025 series and your last chance to improve your ranking. It promises to be an exciting 210nm slalom through the beautiful landscapes of the Aeolian Islands. Our Moody S38's will take off from Tropea and sail west between successive islands to reach the finish line in the Gulf of Palermo.
Fair Winds.
Race #1991
INFO from brainaid.de
Moody S38 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking:
ARQ4 - ARCH - SUPSOL - SYC
Race starts: Dec 15th 17:00 Registration Open!
▶ Flash
GO TO RACE

Chatham Island TIMED Chase 2025

The final TIMED race of 2025 takes us to the isolated and mysterious Chatham Islands archipelago 430 nm east of New Zealand’s South Island. There promises to be plenty of breeze from every point on the compass as we sail the Farr 38 around Chatham Island, Pitt Island, and The Forty Fours on this 124 nm course. This is a TIMEDrace so you may RE-REGISTER HEREto try again after finishing a run. You will have 13 days and 11 hours to test your skill and decision making after the race opens.
Race #1990
INFOby brainaid.de
Farr 38 Particulars
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking:
TRQ4 - TRCH - SUPSOL - SYC
RACE CLOSE: Saturday,
27 December at 23:00 UTC
Race starts: Dec 14th 12:00 Registration Open!
▶ Flash
GO TO RACE

Christmas to Christmas Island 2025

Two waypoints, start and finish, and between them 5827 NM of two oceans. Not much time if we want to sit at the Christmas Eve table. You will need to maintain an average speed of over 10 knots, maybe quite possible with this Maxi Trimaran, but prepare your vessel well and choose the best of the many possible routes. Hands up everyone who knew there were TWO Christmas Islands?! OK, maybe you have sailed this Sailonline course before... but it's time to get ready for the 2025 challenge of racing between Christmas Island in the Pacific to Christmas Island in the Indian Ocean! It also marks the conclusion of our prestigious Ocean Race Championship 2025. Please have fun! Fair winds!
PRIZE: SMPF
Race #1967
INFO by brainaid.de
Maxi Trimaran PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: OCQ4 - OCCH - SUPSOL - SYC
RACE CLOSE: Wednesday,
December 24 at 2300 UTC.
Race starts: Dec 01st 11:00 Registration Closed
▶ Flash
GO TO RACE

Go to race archive

SYC Ranking

  1. Sailonline Yacht Club Member KaSToR
  2. Sailonline Yacht Club Member CriticalHippo
  3. Sailonline Yacht Club Member WRmirekd
  4. Sailonline Yacht Club Member rafa
  5. Sailonline Yacht Club Member vida
  6. Sailonline Yacht Club Member CollegeFund
  7. Sailonline Yacht Club Member bonknhoot
  8. Sailonline Yacht Club Member Panpyc
  9. Sailonline Yacht Club Member sassy63
  10. Sailonline Yacht Club Member BRENTGRAY

View full list

Series

Mobile Client

SYC members have the benefit of access to our mobile/lightweight web client!

The mobile client