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:

Great Bear Ice Race 2025


You can fly to Great Bear Lake Airport, but if the ice is good, instead hire a pick-up truck, load your disassembled DN into the cargo bed and drive, first following the McKenzie River north, and then straight across the lake to the start of our final Ice Boat series race of roughly 100nm in length. The Airport authorities have agreed to leave all lights on, so you should just about be able to see where you are going as you zing and rumble, PL-free over the ice!
Race #1853
INFOby brainaid.de
DN PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: DN - SYC
Race starts: Dec 07th 09:00 Registration will open soon
▶ Flash
GO TO RACE

Christmas to Christmas Island 2025

Two waypoints, start and finish, and between them 5827 NM of two oceans. Not much time if we want to sit at the Christmas Eve table. You will need to maintain an average speed of over 10 knots, maybe quite possible with this Maxi Trimaran, but prepare your vessel well and choose the best of the many possible routes. Hands up everyone who knew there were TWO Christmas Islands?! OK, maybe you have sailed this Sailonline course before... but it's time to get ready for the 2025 challenge of racing between Christmas Island in the Pacific to Christmas Island in the Indian Ocean! It also marks the conclusion of our prestigious Ocean Race Championship 2025. Please have fun! Fair winds!
PRIZE: SMPF
Race #1967
INFO by brainaid.de
Maxi Trimaran PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: OCQ4 - OCCH - SUPSOL - SYC
Race starts: Dec 01st 11:00 Registration Open!
▶ Flash
GO TO RACE

Sinbad by Balloon 2025 - Carnarvon to Dondra


From here, our home in Bharatavarṣa is now north west of us – said Sinbad to his fellow balloonists. Perhaps we can ride the wind first further north, and then catch the winds that every year bring the rain, perhaps not. It’s 2600nm and we could be aloft awhile, so, Master el-Quarters, victuals only, no sandbags, provisioning the giant hamper. It will be not a picnic!
Race #1886
INFOby brainaid.de
SOL Balloon PARTICULARS
WX Updates:
0430 / 1030 / 1630 / 2230
Ranking: SYC - SBB
RACE CLOSE: Tuesday,
December 9 at 2300 UTC.
Race starts: Oct 15th 11:00 Registration Closed
▶ Flash
GO TO RACE

Go to race archive

SYC Ranking

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

View full list

Series

Mobile Client

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

The mobile client