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 » Navigation problrm

Posted by
etxnebe


Users avatar

Posts
6
Registered at
2007-12-23 10:29:47
2008-06-01 19:16:32 - Navigation problrm
If I set a course on the goal line I expext to end up in the goal not 15 nm to the north. I had activated Great circle navigation and saw tyhat the course line was curved but when I
checked why my boat was stranded I saw
that it had sailed in a stait line not as shown on the map when a doid set the course (last rare to Boston previouse race same problem on Hawai).

Can anybody telll me the purpose with great circle navigation idf the boat do not follow the coures set.

Looking forward to some good piece of advise in this matter.

Regards

ETXNEBE
Attachments
Posted by
clash


Users avatar

Posts
4
Registered at
2007-11-20 20:10:24
2008-06-02 14:38:23 - Re: Navigation problrm
Hi etxnebe!
Great circle course is not a "straight" line as CC are!
Following a GC course forces you to change CC now and then.
Try to use the ruler and click along the May Transat rhumbline every 250Nm for example. You will find that you have different CC in most of the "boxes" created by each click!
Any help to You?
clash2
Posted by
Tomas


Users avatar

Posts
19
Registered at
2007-08-10 09:15:02
2008-06-02 14:45:59 - Re: Navigation problrm
Hi!
Great circle nav is just so you can see the "bent" closest route over earth a flat earth and with the course tool pick the initial course.
Lust like in real life you have to alter course manually to follow the great circle.

Compass course is just a angle from magnetic north.

Posted by
Jeroen


Users avatar

Posts
245
Registered at
2007-08-15 09:17:47
2008-06-03 12:02:45 - Re: Navigation problrm
Yeah both remarks are correct.

Great circle nav will give you a indication how your track would be like if you optimize it to take in account the earths bend.

I can understand your confusion becouse it gives a bit the impression this will be the actual course. As said this will require constant adjustments allong the path.

Hope this helps to clear up, sorry to hear you mist the finnish by this.



--- Last Edited by Jeroen Tiel at 2008-06-03 12:03:15 ---
I am a ex-admin of SOL who joins in from time to time.
Posted by
etxnebe


Users avatar

Posts
6
Registered at
2007-12-23 10:29:47
2008-06-03 18:50:05 - Re: Navigation problrm
Hello!

Thanks for all the good explanations to my problem. Shall I conclude this matter by saying that if I set a strait cource to the finish line(no Great circel nav. on) the system will get me there but not on the shortest way. If I use Great circle navigation I will get the shortest way but I have to update the compass cource in regular intervalls to hit the target.

Very best regards

Etxnebe

Please login to post a reply.

Races

Next Race: 00d 00h 00m

Current Races:

Great Nicobar to Marion Island 2025

The Adventure Continues – Leg #6 of the RWW Series.
We’re setting sail on the next stage of the RWW Series: a 4,400-nautical-mile passage from Great Nicobar to Marion Island. This demanding leg will test endurance, strategy, and seamanship at the highest level. As part of the 2025 Ocean Championship, this marks the ninth legendary challenge in the series — and one of the most exhilarating yet. The race will be contested aboard the Archer 78’ ketch, a vessel built to push sailors to their limits across the vast Indian Ocean.
PRIZE: SMPF
Race #1900
INFO by brainaid.de
Archer 78 PARTICULARS    
WX Updates:
0430 / 1030 / 1630 / 2230    
Ranking: OCQ3 - RWW - OCCH - SUPSOL - SYC
Race starts: Sep 01st 11:00 Registration Open!
▶ Flash
GO TO RACE

SSANZ Triple Series 2025 - Race 3

Welcome to the grand finale of this year's SSANZ Triple Series! The stage is set for the Lewmar 50, a thrilling 39nm challenge tracing the southern shores of the stunning Waiheke Island, pushing out to Tarahiki before the sprint back to Islington Bay. Expect fast legs, tactical battles, and no shortage of drama as our SOLers take on the waters in their Young 88s, lining up once again against the talented IRL members of the Young 88 Association. With the series on the line and everything still to fight for, it all comes down to this final race!
Race #1934
INFO by brainaid.de
Young 88 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking:
SSANZ - SYC
Race starts: Aug 29th 21:15 Registration Open!
▶ Flash
GO TO RACE

Red Eye - Myth of Malham 2025

In 1947, Hugh McLean & Sons of Gourock, Scotland built a radical racing yacht for John Illingworth, soon-to-be Commodore of the RORC, to a design by Laurent Giles. With a masthead rig, giving her ‘free’ sail area per the rules of the time, and short overhangs reducing pitching, Myth of Malham went on to win The Fastnet that year and again in 1949, and to compete in numerous Admiral's Cups. In 1958, in honour of the yacht, the Myth of Malham race was conceived - a mini-Fastnet to the first lighthouse on a rock west of Cowes, Eddystone, rather than the second, to be held in non-Fastnet years. IRL this year it has been raced already, but this stops us not from “Red Eye” racing its online 230nm in Fareast 31Rs, leaving how to deal with the Isle of Wight open to your own discretion.
Race #1847
INFOby brainaid.de
Fareast 31R PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: SYC - RED
RACE CLOSE: Monday,
September 1 at 2300 UTC.
Race starts: Aug 25th 12:00 Registration Open!
▶ Flash
GO TO RACE

Africa by Sea 2025 - Maputo to Mogadishu


The fifth leg of our exploration of Africa By Sea takes us north along the length of the Continent’s succulent sub-tropical and tropical Indian Ocean coast. Much fought over by traders and colonists both well-before and after a Portuguese expedition under the command of Vasco da Gama first sailed there from Europe back in the 16th century, it is yet to be properly explored as a yachting destination. With plenty of islands off- and inshore, small and very large, there is much to interrupt your 1900nm voyage and visit in your Swan 65, from Maputo to Mogadishu! Race #1858
INFOby brainaid.de
Swan 65 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: SYC - ABS
RACE CLOSE: Saturday,
September 6 at 2300 UTC.
Race starts: Aug 20th 17:00 Registration Closed
▶ Flash
GO TO RACE

Go to race archive

SYC Ranking

  1. Sailonline Yacht Club Member WRmirekd
  2. Sailonline Yacht Club Member vida
  3. Sailonline Yacht Club Member CriticalHippo
  4. Sailonline Yacht Club Member KaSToR
  5. Sailonline Yacht Club Member rafa
  6. Sailonline Yacht Club Member Kipper1258
  7. Sailonline Yacht Club Member Sax747
  8. Sailonline Yacht Club Member BRENTGRAY
  9. Sailonline Yacht Club Member CollegeFund
  10. Sailonline Yacht Club Member FreyjaUSA

View full list

Series

Mobile Client

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

The mobile client