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

@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

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 ---
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:

Tall Ships Races 2025 - Le Havre to Dunkirk


Welcome to the first of four virtual Tall Ships Races in European waters which are concurrently being organized in-real-life by Sail Training International . The course for this first race is between the French ports of Le Havre and Dunkirk; circa 125nm in Sailonline’s magnificent 90m Barque.
NOTE: Starts and Finishes in tall ships racing are always offshore to avoid conflict with shipping and shipping lanes; online and real-life may not match exactly.
Race #1923
INFO by brainaid.de
Barque 90m PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: TS - SYC
Race starts: Jul 07th 16:00 Registration Open!
▶ Flash
GO TO RACE

Red Eye - Key Lime Pie-gatta 2025

Opposite the Bahamas at the tip of the Florida peninsula, we find the Florida Keys, a honky-tonk arpeggio of islands, where another SOL classic, the Key Lime Pie-gatta, so-called after the famous local condensed-milk-based tart speciality, awaits to be navigated once again. We’ll race its “Red Eye” 180nm in very-American Santa Cruz 52s, ignoring such artefacts as bridges, causeways and piers joining the keys one to the other and to the mainland!
Race #1846
INFOby brainaid.de
Santa Cruz 52 PARTICULARS
NAM_AWIP WX Updates:
0245 / 0845 / 1445 / 2045
Ranking: SYC - RED
Race starts: Jul 02nd 12:00 Registration Open!
▶ Flash
GO TO RACE

Sail Around Turkey 2025


Welcome to the 11th running of one of Sailonline's most iconic races, where our fleet races the length of the Turkish coastline from Hopa (the easternmost harbour on Turkey’s Black Sea coast) to Iskenderun (the easternmost harbour on Turkey’s Mediterranean coast). It’s a 1,372nm race and aboard our classic, 1st decade of the 21st Century, version 2 IMOCA 60, you should be able to get around the course in less than a week. That is if, of course, once you get out of the Black Sea you don’t stop to enjoy the sights or a BBQ or two in the Golden Horn, or on the Marble Islands, now land-locked Troy or Gallipoli or any of the myriad Aegean islands, that you shall have to carefully navigate past.
Race #1930
INFOfrom brainaid.de
IMOCA 60 v2 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: SYC
Race starts: Jun 27th 15:00 Registration Open!
▶ Flash
GO TO RACE

Go to race archive

SYC Ranking

  1. Sailonline Yacht Club Member CriticalHippo
  2. Sailonline Yacht Club Member KaSToR
  3. Sailonline Yacht Club Member WRmirekd
  4. Sailonline Yacht Club Member FreyjaUSA
  5. Sailonline Yacht Club Member rafa
  6. Sailonline Yacht Club Member Kipper1258
  7. Sailonline Yacht Club Member rumskib
  8. Sailonline Yacht Club Member BRENTGRAY
  9. Sailonline Yacht Club Member Patrick70119
  10. Sailonline Yacht Club Member CollegeFund

View full list

Series

Mobile Client

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

The mobile client