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 » Clarify marks

Posted by
Bingalup


Users avatar

Posts
2
Registered at
2011-11-21 13:37:12
2011-11-24 07:32:45 - Clarify marks
In the latest white Island race in the Boats tab there is a list of 5 marks which seem to be different to the "rounding" marks on the map.
What does DTG stand for and the number in the right and left columns

Do you have to pass on a particular side of these marks?
Posted by
Tempest


Users avatar

Posts
79
Registered at
2009-06-16 17:44:17
2011-11-24 17:20:42 - Re: Clarify marks
Mike , the marks in the boatlist are used for practice racing and do not refer to the marks in the real race. These boatlist marks disappear one hour before start
Posted by
NZL_PaulR


Users avatar

Posts
311
Registered at
2008-07-22 12:21:30
2011-11-25 06:45:55 - Re: Clarify marks
DTG = Distance To Go to the finish.

LHS: # = leaderboard position by the shortest DTG by great circle to finish, even though the boats may be many miles apart e.g. horizontally
If it breaks, it's not strong enough!
Posted by
AGage


Users avatar

Posts
411
Registered at
2008-12-27 10:31:57
2012-03-29 14:32:01 - Re: Clarify marks
DTG = Distance to Goal AFAIK...

Just a small point, and thinking it would be better as DTF ;-)
I help develop the client interface for the best online ocean racing sim there is... __/)/)_/)__
Posted by
NZL_PaulR


Users avatar

Posts
311
Registered at
2008-07-22 12:21:30
2012-03-29 22:49:58 - Re: Clarify marks
DTG = Distance to GO, pretty close to GOAL, but not always.
DTF = Distance to Finish.

Whilst they may seem to be the same, there could be a difference because of the shape of the earth. Similar to Great Circle vs Rhumb line.

Another time the FINISH may be the middle of the finish line, but if there is a bias / skewed finish, then distance to GO to the nearest "END" of the line may be shorter and equally can take longer than going to the furtherest "END" of the line.

In the same way, different GPS manufacturers (or software developers) can have slightly different meanings at different times.

E.g. when we do NOT have a destination waypoint active in our GPS, our VMG is Velocity Made Good into the WIND. If a destination waypoint (or Route) is active then our VMG value is really a VMC Velocity Made Good to the WAYPOINT / DESTINATION (if route is not active).

Whilst they can be similar at times they are NOT the same. Argueably the instruments should then show VMC (COURSE) or VMW (WAYPOINT), but they do not.

Similarily the Traverse Tables can give different distance results than simple Mercator chart plotting.

If it breaks, it's not strong enough!
Posted by
AGage


Users avatar

Posts
411
Registered at
2008-12-27 10:31:57
2012-03-30 04:17:59 - Re: Clarify marks
Well on SOL the value is computed to the closest point on the finish line (once on final leg) - but I'm not sure I see how the shape of the Earth can mean Goal and Go differ?

I just meant DTF seems to be a more widely used acronym than DTG...

The nautical software I use shows both VMG and VMC (when a waypoint is defined) - I would think instruments like onboard dont, just to keep the programming simpler - but yeah that could get confusing had you not read the manual fully!
I help develop the client interface for the best online ocean racing sim there is... __/)/)_/)__
Posted by
NZL_PaulR


Users avatar

Posts
311
Registered at
2008-07-22 12:21:30
2012-03-30 09:54:24 - Re: Clarify marks
and not all manuals are the same!!!
If it breaks, it's not strong enough!

Please login to post a reply.

Races

Next Race: 00d 00h 00m

Current Races:

The British Isles Circumnavigation 2026


The British Isles Circumnavigation is here! Inviting skippers to take on an epic 1,720nm clockwise voyage around Britain and Ireland! Starting and finishing in Cowes, the course passes some of the most iconic landmarks in offshore sailing, including Fastnet Rock, Tearaght Lighthouse, Black Rock, St. Kilda and Muckle Flugga before the long run home. Racing in our fast and versatile TP52, this Super-Buddy Championship race will reward smart routing, changing weather strategy and sustained concentration over every mile. Good luck!
Race #2052
INFO by brainaid.de
TP-52 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: SUPBUD - SYC
Race starts: Aug 09th 10:00 Registration Open!
▶ Flash
GO TO RACE

SSANZ Triple Series 2026 - Race 2

Welcome back to race two of the SSANZ Triple Series—it's time for the Lewmar 100! Our dynamic fleet of Young 88s returns for another exhilarating 65 nautical mile battle across the stunning waters off Auckland, New Zealand. Once again, our skilled Sailonline racers will test their strategic minds and endurance. With intense competition, shifting conditions, and plenty of tactical decision-making, this race promises high-energy sailing and edge-of-your-seat excitement from start to finish!
Race #2047
INFO by brainaid.de
Young 88 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: SSANZ - SUPBUD - SYC
Race starts: Aug 08th 21:15 Registration Open!
▶ Flash
GO TO RACE

Lake Vättern PYOC 2026


Back in 2013, longstanding SOLer Musigny and his friend xthyra invited us for a three race tour of beautiful Lake Vättern in the heart of southern Sweden. After many years, we return there for a quick sprint from a start in front of the village of Brandstorp, either way around Visingso island in the middle of the lake, but PORT HAND ROUND a buoy off the Granna piers on the eastern shore and back, once again avoiding Visingso as best you can. At least 20nm in trusty Scandinavian 11m One Designs; good luck!
Race #2046
INFO by brainaid.de
11m OD PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: SPQ3 - SPCH - SYC
Race starts: Aug 08th 21:00 Registration Open!
▶ Flash
GO TO RACE

Easter Island to Tristan da Cunha 2026

Welcome to the second leg of our RNW series, rounding Cape Horn. This middle-most leg Round the New World, from Easter Island to Tristan da Cunha, is also part of our Ocean Championship, and as such the second race of OCQ3 2026. This race, like the previous race in the RNW series, will be sailed in our revised 'version 2' Imoca 60 Foil. Race #2050
INFO by brainaid.de
Imoca 60 Foil v2 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: OCQ3 - RNW - OCCH - SYC
Race starts: Aug 03rd 11:00 Registration Open!
▶ Flash
GO TO RACE

Magical Mediterranean 2026 - Benghazi to Korcula

We return to Antiquity’s Middle Sea for a seventh celebration of all things Mediterranean - fickle winds, history and olive oil. This time we will sail from ancient Benghazi, whence once grain shipped continuously to feed Rome’s urban masses, to the medieval Venetian thalassocracy’s port of Korcula, birthplace of Marco Polo; 700nm in classy Club Swan 50s!
Race #1978
INFO by brainaid.de
Club Swan 50 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: MED - SYC
RACE CLOSE: Friday,
August 7 at 2300 UTC.
Race starts: Jul 27th 15:00 Registration Closed

▶ Flash
GO TO RACE

Go to race archive

SYC Ranking

  1. Sailonline Yacht Club Member KaSToR
  2. Sailonline Yacht Club Member WRmirekd
  3. Sailonline Yacht Club Member CriticalHippo
  4. Sailonline Yacht Club Member Panpyc
  5. Sailonline Yacht Club Member rafa
  6. Sailonline Yacht Club Member cdhinman
  7. Sailonline Yacht Club Member rthinman
  8. Sailonline Yacht Club Member ms0689
  9. Sailonline Yacht Club Member BRENTGRAY
  10. Sailonline Yacht Club Member Sax747

View full list

Series

Mobile Client

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

The mobile client