VSK5 or 32^nd America’s Cup version of the game comes with four default models:

• ACC
• Offshore
• Multi Open
• Melges

Various talented individuals in the VSK community have developed additional models that can be installed into the game these models are referred to as “Custom Models”.

There are at time of writing these models available:

All these models are compatible with VSK5 or 32^nd America’s Cup. (Patched)

VSK4 models (not listed here) are compatible with VSK5 but perform poorly.

Generally, models need to be heavily upgraded before they are suitable for use in the modern game.As you will learn over the following pages, if you look at a “Polar Diagram” for a model from VSK4 and compare it with a VSK5 models diagram you will find many “Polars” are either missing some or all of the information.

Most of these models can be found to download at:

http://www.vsk-aus.com/ - Australia

http://www.virtual-winds.com/modules/news/ - Europe

http://www.vskfun.com/VSKFunReloaded/ - Europe

Plus many other VSK sites.

This is a link to the Official Forum of VSK:

http://www.virtualskipper-lejeu.com/forum/index.php

Here is a link to a listing of all the VSK club sites:

http://www.virtualskipper-lejeu.com/forum/viewtopic.php?t=4423

Custom Boat racing – Reading Polar Diagrams

In VSK5 or 32^nd America’s Cup version of the game one of the options Custom Boat xml creators have is that they can give those who wish to sail under “Manual” trim over those using “Auto” trim.These skippers can easily outsail their fellow competitors who are “Auto trimmers.” Nadeo boats however do not give any advantage to those who wish to sail using manual trim unlike VSK4 which did.

With all the default Nadeo Boats - ACC, Melges, Multi & Offshore, it is best to sail using Auto trim.
Any player who has the paid version of the game has access to "Editors" within the game menu. This is a tool which enables you to view the "Polar Diagrams" of the particular model you are sailing.

To View these:

1. Start the Game
2. Select Editor
3. Either Select a Race to edit or create a new race
4. Select the model in "Params"
5. If you created the race, save it before you play it.
6. Select "Play"
7. Press the "9" key above the "I & O" keys on the keyboard to view the "Polar Diagrams" (Not the "9" key on the Number Keypad, as this will not show the Polar Diagrams.)
   

• You can swap views of the different sails using the left scroll arrows depending on what sails the model has.
• You can view the different sail properties using the centre scroll arrows. There are ten different views but you will mainly be interested in “BoatSpeed” & “BSCoef”.
• You can also narrow down the view to different wind strengths using the right scroll arrows e.g. either the 0kt, 5kt, 10kt,15kt,20kt, 25kt, 30kt or 40kt curves.

Boat Speed

In "BoatSpeed" the Diagram represents the points of sailing with top centre - 0 degrees being "Head to Wind" 90 & 270 degrees "Reaching" and 180 degrees "Dead Square" the other guide lines are for 30, 60, 120 & 150 degrees.

The Radial guide lines are for the Boat speed in Kts. As you can see the different colour pattern lines show the Boat speed in Kts at particular point of sailing. With this view you can see at which point performance drops off or spikes.

Remember that you will need to also view the other sail you are using at that time.
Eg: To windward you would be using one of the headsails, downwind the spi.Generally the headsail will give you the information you might need.

BS Coef

The "BSCoef" Polar Diagram is more complicated but for this exercise I'll explain what you need to look for. The outer ring of the guide lines represents "1" as a Co-Efficient of BoatSpeed ( BSCoef ).

The 0.8 ring is 80% of BoatSpeed, the 0.6 ring is 60%, the 0.4 ring is 40% etc.

On Nadeo boats at no point is the figure greater than "1" - that is the reason why Auto is always better than Manual.

The way we overcome this with Custom Models is by giving a BSCoef greater than "1" sometimes up to "1.1" as this gives a 10% advantage however this may be in light winds only, "1.05" is more often used (5% advantage).

• What do you Look for?
• Which way do you sheet? (in or out)
• How Much?
  

BS Coef Imoca

Note on the Polar Diagram above that there is a spike greater than "1" also note that it is to the right side of the centre - this means there is an advantage if you sheet in a little. Also note that the spike is consistent across the TWS ranges and sail points. This means the advantage is on all points of sailing. How much - well VMG in your instruments is useful as well some xml guru's give visual clues such as the boat heals quickly when you have under / over sheeted too much.

BS Coef 18 foot Skiff

Note on the Polar Diagram above that there are spikes greater than "1" to the left of side of centre, this means that you need to Out sheet to gain an advantage. With a Model like the 18 Foot Skiff the visual clue is to sail the boat flat.

BS Coef Maxi Cat

On some models you might find that it changes whether you sheet in or sheet out depending on TWS, scroll though the TWS views to note when this change occurs.

BS Coef Tornado 24knts

Note that in this Polar Diagram that there is a spike but it is not consistent across the sail points, it is only present within a small AWA range (Apparent Wind Angle). This means that unlike most custom boats there is no advantage upwind or downwind using manual trim, only on reaches is there an advantage. It is not possible to read this information on this Polar as the points of sail are all the same colour; the Tornado is unique in this regard as far as I know. At this wind strength the sail needs to be Sheeted in to gain an advantage. Sailing the model and looking for an advantage in VMG is the best method, looking for visual clues. (Heal angle etc.)

BS Coef Tornado 24.2 Knts

Observe that in this Polar the advantage has now shifted to the left of centre, this means that the sail need to be Out sheeted but like the last example the advantage is not across the range of AWA but only a small range.

Optimal Sail Angle - Sails "Blowing Out"

Some Custom Boats and the Nadeo Multi Open 60's Code O (Sail 3), have a feature that above a certain Wind Strength there headsail "Blows Out".
In the game you see this effect when the sail concerned automatically eases and flaps - it cannot be trimmed to set above a certain threshold wind strength. This section explains how you can read Polar Diagrams to see not only that this will happen, but also the wind strength at which it will happen.

On the Polars screen use the centre arrows at the bottom of the screen to scroll to the "OptimalSailAngle" polar diagram, and use the left hand arrows to select which sail you wish to view.The example above shows the following things:

• The selected sail is the CodeO.
• The radial lines coming outwards from the centre of the diagram at 0, 30, 60, 90, 120, 150 and 180 degrees etc. represent the angle of sail.
• The numbers on the 0 - 180 radial line are in 20 degree increments are the "OptimalSailAngle" in degrees. (this is shown at the centre top of diagram).
• The coloured polar rings represent different wind strengths - observe the key in the top left corner of the diagram.

If you look closely the 32 knot curve does not exceed 60 degrees of the "OptimalSailAngle" except when pointing higher than 30 degrees (i.e. when tacking, the sail will not set and will flap). However the 32.1 knot curve is always above 100 degrees (more when running deep downwind). This means the sail will not set - it will flap - above 32.1 knots, and performance will be lost. Change down to a smaller headsail to restore speed

Custom Boats - No wind Arrow

Windshadow