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 Discussion » Do All Boats Start The Same ?

Posted by
A2


Users avatar

Posts
347
Registered at
2009-10-26 00:39:42
2015-01-07 21:16:06 - Do All Boats Start The Same ?
Since the Free Turn artifact has been 'fixed' it brings to mind another starting issue that occasionally has been discussed in chat relating to the way boats appear on screen at the Gun. In the very beginning some boats seem to get out of the gate sooner than others. So I was wondering if this is indeed the case in fact or simply a lag in the way fleet positions are reported to the client.

From careful observation & astute deductive reasoning I am in the camp that believes the former to be the case. Which begs the questions what if anything can be done to get to the front of the queue. Also does the ranking of boats prior to the start of any race indicate the sequence in which the server will execute steering instructions on their behalf ?

Granted a single jump advantage early on is rarely decisive by the end of any race but it is a definite psychological boost when reaching the 1st mark or headland down the course.
None so blind
Posted by
hmm


Users avatar

Posts
118
Registered at
2011-11-03 13:35:22
2015-01-08 20:58:49 - Re: Do All Boats Start The Same ?
The short answer is that all boats start at the same time if they have set a starting command.

The sailing engine which takes care moving of the boats has been written by Jakob and Kalle, the original founders of SOL and I can't say I know it thoroughly. This is my best explanation on what happens though.

Practically what happens is that the server calculates boat movements one boat at time and when starting there are hundreds of boats starting at the same time.

There is no particular order in what the boats are moved, it happens in the order the underlying database SOL uses happens to list them. I suppose databases tend to internally provide data in same order which depends on how it's internal data structures stores the data, it can be related to the order data has been written in the database but not necessarily always so.

When the moving happens in sailing engine there is a separate program handling the caches. Every 30 seconds it will take a snapshot of every boat's position and store it to server memory. When SOL clients connect to server for asking the fleet position this snapshot is what they get. This is to prevent the need of every client individually asking from the database the positions of all boats.

When this snapshot is taken, it can happen when the sailing engine is in the middle of moving the boats so in the image you can see some boats further than others. In my opinion this explains most of the differences you can see in boat movements just after start.

There might be more things affecting the issue (I think the sailing engine has some kind of method where it will detect high load situations and move boats less frequently) but to me the sailing engine is good enough and at least I don't know any way to always get a "front line start".

Posted by
Rod


Users avatar

Posts
392
Registered at
2010-06-24 22:30:48
2015-01-09 13:50:57 - Re: Do All Boats Start The Same ?
In the practice races, I have almost always observed that boats starting at the same time, and following the same course, (at presumably the same speed), will maintain the same order until the first rounding, (15 min or so later). This would suggest that the server maintains a list of boats, and moves the boats in the same order, at least until the list is disturbed by different orders being given by the helmsman.
If it breaks, it's not strong enough--if it doesn't, it's too heavy.
Posted by
Bimmer


Users avatar

Posts
447
Registered at
2015-02-23 15:38:27
2016-03-08 08:49:05 - Re: Do All Boats Start The Same ?
Hi Rod
In practice races it is the boats distances to the next waypoint in the actual race that is measured and can be seen on the ranking list, and not the marks we use in PR, so you have to trust your eyes here :-)

Bimmer

Please login to post a reply.

Races

Next Race: 00d 00h 00m

Current Races:

Rapallo to Nador 2026


Welcome to Liguria’s Rapallo, there where Zarathustra spoke - at length - to Nietzsche, for our first race of nine to celebrate all things Mediterranean - fickle winds, history and olive oil. A number of our races in this new Magical Mediterranean series will be partnership with famous real-life races, but this first race is pure fiction - 780nm in refurbed IMOCA 60s, past or through the Balearic Isles and on into the Alboran Sea, to a finish off Nador on the Maroc Mediterranean coast.
Race #1975
INFOby brainaid.de
IMOCA 60v2 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: MED - SYC
Race starts: Mar 30th 15:00 Registration Open!
▶ Flash
GO TO RACE

Red Eye - Melville Island PYOC 2026

Melville Island is the largest of the Tivi group opposite the port of Darwin in the Timor Sea. Tropically forested and thinly populated, not a lot goes on there, but let’s race around it anyway, lar- or starboard round, it’s a little more than 120nm, so, no matter where you are navigating from on the planet, you will be hard-pressed to complete the course aboard your J-80 in daylight hours!
Race #2003
INFOby brainaid.de
J-80 PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: RED - SYC
RACE CLOSE: Tuesday,
March 31 at 2300 UTC.
Race starts: Mar 24th 12:00 Registration Open!
▶ Flash
GO TO RACE

Cross the Convergence 2026 - Guam to Ouvéa


The third race of our series of ocean voyages across the World’s convergence zones takes us southeastward now down the Pacific, from Guam’s Apra Harbour at 13.5 degrees North, back across the Equator to the glorious New Caledonian resort island of Ouvéa, on the edge of the Tropic of Capricorn at 20.5 degrees South. It’s 2400nm, and there’s more than a few other islands in the way, so mind where you go in your Ocean 50s. Race #1981
INFOby brainaid.de
Ocean 50PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: CCZ - SYC
Race starts: Mar 20th 18:00 Registration Closed
▶ Flash
GO TO RACE

Lake Victoria TIMED Race 2026

This month’s TIMED race takes us inland to Lake Victoria in the heart of Africa. Starting at Rosebery Channel in Uganda sail the AC72v2 on a 196nm course around Bugala Island on the way to the finish line in Tanzania’s Speke Gulf. 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 #2018
INFOby brainaid.de
AC72v2 Particulars
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking:
TRQ1 - TRCH - SYC
RACE CLOSE: Saturday,
28 March at 23:00 UTC
Race starts: Mar 15th 12:00 Registration Open!
▶ Flash
GO TO RACE

Go to race archive

SYC Ranking

  1. Sailonline Yacht Club Member WRmirekd
  2. Sailonline Yacht Club Member KaSToR
  3. Sailonline Yacht Club Member rafa
  4. Sailonline Yacht Club Member rumskib
  5. Sailonline Yacht Club Member Sax747
  6. Sailonline Yacht Club Member vida
  7. Sailonline Yacht Club Member CriticalHippo
  8. Sailonline Yacht Club Member CollegeFund
  9. Sailonline Yacht Club Member Panpyc
  10. Sailonline Yacht Club Member sassy63

View full list

Series

Mobile Client

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

The mobile client