The Rules, (Full version)
All calculations use Great Circle Route formulas and the WGS84 reference frame.
Great Circle Route - Wiki
WGS84 - Wiki
Aviation Formula V2.1 by Ed Williams
Your Route
1. At the beginning of each
Leg Boats line up along the Start Line - 1/10 nautical mile apart.
2.
Your Crew consists of all 15 members of your squad and each ones GW points constitute a Tack - making 15 tacks per GW. For your Skipper base points are used - not points X 2.
3. The order the Tacks are taken in is that of the
Player Number as they appear on your team page after auto-subs have been made at the end of a GW. Your first choice Goalkeeper will always be Crew Member 1, followed then by your Defenders, Midfielders, Forwards, Sub GK (always No.12) and then your remaining Subs.
4. To give some direction to those Tacks each Leg consists of a series of
Waypoints to which an
Initial Bearing is taken at the start of each Tack.
5. That
Initial Bearing is then adjusted dependant on your Team the previous GW. Again Players (
Navigators in this case) are numbered 1 to 15 and the difference between the Crew points and Navigator points is used to determine your
Navigation Error away from the perfect line to your Target Waypoint. The Difference is an Absolute value - so 10-3 gives the same results as 3-10 (7).
6. If your Crew member is playing at
Home you will be making a
Starboard Tack -
Away gives a
Port Tack.
7. Once a Waypoint has been passed your target becomes the next Waypoint on the Route - until the Leg Finish line is crossed. A Waypoint is passed when your Track intercepts the Waypoint's
Wayline. The Wayline passes through the Waypoint such that the angle it makes with the Previous and Next Waypoints is equal. Waylines for the Start and Finish are at right angles to the next and previous Waypoints respectively.
Examples of Start, Mid-Leg and Finish line Waypoints and Waylines


When your Tack crosses a Wayline the Tack ends - however any "unused" Crew points will be added to the start of your next Tack. This is done so that each GW consists of only 15 Tacks and was the simplest way of achieving this while also ensuring that all points earned were used.
8. Each Waypoint has 2 values associated with it - the
Distance per Point and
Max Nav Error.
Distance per Point. Determines the distance in nautical miles (nm) you travel on the Tack, per point scored, while the specific Waypoint is your current Target. This figure is smaller when starting a Leg than it is when in the open ocean and can also be adjusted to speed up/slow down the race should it fall behind/ get ahead of the planned schedule if needed.
Max Nav Error. While your Navigator determines your Boat's Nav Error each Waypoint has a Maximum Error permitted. This figure is in Degrees and can be lower for early Waypoints and can increase to 90° when in the open ocean.
In other words - if your Target Waypoint has a Max Nav Error of 90° and the difference in points between your Crew Member and Navigator is large your Tack will be at right angles to where you really want to be going.
Examples of how it might go - Good and Bad

Incidents/Bonuses
Man Overboard
A
Red Card for your Crew member translates as a Man Overboard. The Tack in question will proceed as normal with the M.O. occurring at the end of the Tack. Subsequent Tacks will be discarded - the number being dependent on whether assistance reaches you.
At the beginning of the next Tack the closest 2 Boats (within your Pool and who are Racing and have the same Target Waypoint) will immediately change course to come to your assistance (for 1 Tack only and on a direct Bearing). If either of these Boats reach you within that Tack you will only lose only that Tack - if not you lose 2 Tacks worth of sailing.
A Boat is Racing if they are not involved in any incidents themselves - ie a Man Overboard or a Run-Aground (including Making Repairs or Returning to a Restart point).
If there are multiple Man Overboards and a Boat is one of the closest 2 to more than 1 Boat requiring assistance they will proceed towards the closest to them. In this case another Boat (the third closest etc) will respond to the SOS. This process repeats until there are no Boats left to respond.
Running Aground
If you Run Aground (your Boat sails into any land mass, large or small) the remainder of that Tack and the next 1 will be discarded while you make repairs.
Once repairs have been made your re-start position will be the position your Boat was in at the start of the Tack that originally caused you to Run Aground. Depending on your new Bearing you could either Run Aground again or sail free of any obstacles. (Starting a Tack within a group of Islands can be tricky to escape from).
If you Run Aground a second time from your original Restart position you will then Restart from the last Waypoint you passed. (This is to prevent Boats becoming completely stuck in places that would be impossible to escape from).
Note: If a Boat is returning to it's previous Waypoint (after Running Aground twice) the Track displayed may cross land but as the Boat isn't actually Racing at the time this is OK - it's just there so there are no gaps in the Track.
Overall Leader Board
1.
The Fleet will be split into a small number of
Pools (3 or 4). This is to keep things manageable but your Boat will not necessarily be in the same Pool for the whole race. The Pool membership for the first Leg will be random but those for later Legs will be based on your Race Points at the time. (Exact rules for this will be announced closer to the Race Start).
2. Points will be awarded in each Pool dependant on your Leg Finishing position. If your Pool has 15 members, say, the Leg winner will get 15 points, second 14, down to 1 for last. Points will also be given to any Boat that fails to complete a Leg within the Schedule. This will be on the basis of their distance to their Target Waypoint and the order that Waypoint appears along the Ideal Route.
Non-finishers will also be allowed to compete in the next Leg.
3. The Overall FGC winner will be the Boat that accumulates the most points over the whole Race.
4. These Rules may be tweaked in some way for the final 2GW Leg.
That's roughly how it goes
Sorry if it's a bit confusing at the moment but it's the nature of the beast. (With current Boat numbers there will be approx 24000 separate Tacks during the race

)
It will become clearer later and as the Race gets underway. All the data used, Points, Bearings, Distances and Incidents etc will be clearly shown in the Placemarks within Google Earth.