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 » Technical Support » distance to go

Page: Previous 1 2

Posted by
Olive


Users avatar

Posts
4
Registered at
2012-12-24 20:22:03
2012-12-30 09:18:14 - Re: distance to go
That's all indifferent since the nonsense numbers lead us all astray. Who cares if it all makes sense when we "get close." Why play along at all. Sheeeze...
Posted by
RainbowChaser


Users avatar

Posts
2656
Registered at
2009-06-14 09:44:50
2012-12-30 09:22:52 - Re: distance to go
evilonod - I can sympathise with your frustration, but rest assured there is no-one getting any advantage here. It really is all about the shape of the globe and how SOL's calculations are made.

Please don't give up on us!
Posted by
hmm


Users avatar

Posts
118
Registered at
2011-11-03 13:35:22
2012-12-31 10:06:10 - Re: distance to go
I believe I have now found the root cause of this problem. I have described it in my blog:

http://blog.sol.hmm.iki.fi/2012/12/scoring-problem-on-races-crossing-idl.html
Posted by
outlaw


Users avatar

Posts
33
Registered at
2012-06-01 13:37:55
2012-12-31 17:07:52 - Re: distance to go
As for the DTF calculations, how about simply calculating GC bearings to the next couple waypoints, then using GC distance to the best WP based on bearings + rounding direction. I suspect this may lessen server load as well. (see pic)
Attachments
Posted by
hmm


Users avatar

Posts
118
Registered at
2011-11-03 13:35:22
2013-01-02 11:45:03 - Re: distance to go
I have also tried to explain the DTF calculation in more detail in my blog, check the post here:

http://blog.sol.hmm.iki.fi/2013/01/dtf-calculation-problems-near-polar-area.html

As I say in the post, the DTF calculation is run every 15 seconds for each boat, so changes to that code have to be made very carefully not to cause the server too much load.

However, that doesn't mean that there will not be improvements in the future. It just means that the changes have to take into account also other things than only always getting the best possible DTF for the boat.
Posted by
Rod


Users avatar

Posts
392
Registered at
2010-06-24 22:30:48
2013-01-02 14:26:49 - Re: distance to go
Is it not possible for each player (sailor ?) to merely run the measuring caliper tool, in Great Circle mode, between the next turning mark and the current position of any boat (including his own) in which he has an interest?
I just do not understand the cause of all this worry over such a trivial problem.
Congratulation to Markku H. for solving the causes of the SERVER'S problem, but it is really not a problem to the SAILOR.
If it breaks, it's not strong enough--if it doesn't, it's too heavy.
Posted by
outlaw


Users avatar

Posts
33
Registered at
2012-06-01 13:37:55
2013-01-02 18:32:12 - Re: distance to go
> the DTF calculation is run every 15 seconds for each boat

This is unneeded, do a proper distance calculation every 16 steps, and use increments (VMC * timestep) inbetween.

That means only one in 16 boats gets a full calculation for a given timestep.

The same could be done for roundings, maybe.

--- Zuletzt bearbeitet von outlaw am 2013-01-02 18:33:23 ---
Posted by
hmm


Users avatar

Posts
118
Registered at
2011-11-03 13:35:22
2013-01-02 19:25:05 - Re: distance to go
To do that the VMC (and the course which to calculate VMC for) should be calculated for each boat every 15 seconds so it's not clear if it's easier to it that way.

The VMC, VMG etc numbers you see at the client are calculated at in your own computer and are thus "cheap" for the server but on the other hand are not available there directly.

It's good to have different ideas how to improve the calculation but as Rod wrote earlier I don't see it as a major problem now.
Posted by
Hasseballad


Users avatar

Posts
17
Registered at
2008-11-15 11:51:32
2014-05-25 07:33:33 - Re: distance to go
Recent experience at RTW2014-leg4. The "rounding line" ref. hmm for Cape Horn has a limit at 83S & 34W. Why not move that limit to say 65S & 64.2W or the exact W pos. on the "rounding line". Wouldn't that be a simple improvement for the boat position at the Horn specificly.

Rgds Hans

Page: Previous 1 2

Please login to post a reply.

Races

Next Race: 00d 00h 00m

Current Races:

Valparaiso to San Francisco 2025

Get ready for an exhilarating new challenge as we set sail on the fourth leg of the 2025 Ocean Championship Series! Following in the 19th century footsteps of Isabel Allende's heroine, Eliza Sommers, 'Daughter of Fortune', this all-new route takes us across the vast eastern Pacific, from Valparaíso, Chile, to San Francisco, California - a 3500nm journey of endurance, strategy, and pure sailing adrenaline. This leg will be raced aboard the powerful Rapido 60, pushing sailors to their limits as they navigate the open ocean. Do you have what it takes to conquer the Pacific? Join us and put your skills to the ultimate test!
PRIZE: SMPF
Race #1900
INFO by brainaid.de
Rapido 60 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: OCQ2 - OCCH - SUPSOL - SYC
Race starts: Apr 07th 11:00 Registration Open!
▶ Flash
GO TO RACE

Red Eye - Round White Island 2025

We remain in New Zealand for our second “Red Eye Special” and another IRL Kiwi classic - the Round White Island! IRL still “currently on hiatus” following the island’s eruption of 2019, this race was last raced on SOL in 2020. It’s about 300nm there - out the Hauraki Gulf and south down to the island in the Bay of Plenty - and back to Auckland. This year we’ll be racing in our ever-popular take on the TP-52. Hau tika!
Race #1844
INFOby brainaid.de
TP-52 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: SYC - RED
Race starts: Apr 06th 12:00 Registration Open!
▶ Flash
GO TO RACE

Moheli PYOC 2025


For our first sprint of Q2, we will re-visit the African archipelago nation, L’Union des Comoros, and its most southern island, Moheli, in the Mozambique Channel. Created by MustangMark in 2014 this is a “Pick Your Own Course” round the island, approximately 20nm in our First 27. Expect winds to be light and variable; we are in the Tropics.
Race 1907
INFO by brainaid.de
First 27 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking:
SPRQ2 - SPRCH - SUPSOL – SYC
Race starts: Apr 05th 09:00 Registration Open!
▶ Flash
GO TO RACE

Africa by Sea - Tangier to Abidjan


Whatever about pharaoh Necho II’s Phoenician expedition of the 7th C BCE, the Carthaginian Hanno the Navigator with more certainty sailed south from Tangier to explore the West African coast two centuries later, but how far he got is a matter of more conjecture. However, if he did the 2300nm to today’s Ivory Coast he would have found little there other than good shelter in the vast lagoons behind the dunes, much the same as today, excepting the highly industrialized port of Abidjan. Not a great haven for a stop-over but let’s take the 90ft Monohull anyway.
Race #1855
INFOby brainaid.de
90ft Monohull PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: SYC - ABC
RACE CLOSE: Thursday,
April 10 at 2300 UTC.
Race starts: Mar 26th 17:00 Registration Closed
▶ Flash
GO TO RACE

Sea Lion TIMED Race 2025

Come on down South for long days of sunlight and strong bracing winds to race our Finngulf 43 as many times as you like - 117nm as the albatross flies - through some of the islands of the Falklands archipelago. This is a TIMED race, so you may RE-REGISTER HERE to 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 #1903
INFO by brainaid.de
Finngulf 43 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking:
TRQ1 - TRCH - SUPSOL - SYC
RACE CLOSE: Saturday,
05 April at 23:00 UTC
Race starts: Mar 23rd 12:00 Registration Open!
▶ Flash
GO TO RACE

Melbourne Osaka Cup Double-Handed Yacht Race 2025

Welcome once again to what these days is Sailonline’s almost annual virtual Melbourne to Osaka Yacht Race. In real life, this double-handed 5500 nm race between these two sister cities, one deep in the southern hemisphere, the other high in the northern hemisphere, is run every four to five years, and this year is such a year. So, this year’s online version is in sync with the Melbourne Osaka Cup 2025 organised by the Ocean Racing Club of Victoria (ORCV), and the Sandringham (SYC) and Osaka Hokko (OHYC) yacht clubs. We’ll be racing the well-known First 40, a popular size of boat which should be a good match for many of the boats entered in the real race. With the doldrums unavoidably lying across our course, you can expect to be at virtual sea for at least a month!
Race #1669
INFO by brainaid.de
First 40 Particulars
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: SYC
Race starts: Mar 16th 06:00 Registration Closed

▶ Flash
GO TO RACE

Go to race archive

SYC Ranking

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

View full list

Series

Mobile Client

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

The mobile client