International America’s Cup Class

The International Americas Cup Class is a class of sailing vessels that was developed for the America's Cup competition. These yachts which, while not identical, are all designed to a particular formula, so as to make the boats involved in a competition roughly comparable, while still giving individuals the freedom to experiment with the details of their designs. The class was established prior to the 1992 America's Cup because of perceived shortcomings of the 12-metre class, which had been used in the America's Cup since 1958. Previously, J-class yachts were used.

In addition to the America's Cup, IACC yachts are raced in other regattas, including the IACC worlds

IACC Sail numbers

IACC sail numbers are issued according to the date the ACM Measument committiee decides the hull has reached a certain stage of completion. The number comes in two parts the country of ownership represented by the three letter prefix, and the hull number. The country code changes as the hull is transferred from country to country. Only one boat had a sail number issued twice as in the case of RUS-62 which was a new boat based on the heavily modified hull of RUS-24 and re-registered as RUS-62.

IACC Rule

Version 5.0 of the International America's Cup Class Rule was issued on December 15, 2003. Copyright held jointly by the "Defender" Alinghi and the 'Challenger of Record' BMW Oracle Racing.

Typical parameters of an IACC yacht are:

* Length: 25 metres
* Weight: 24 tonnes
* Height of the mast: 35 metres
* Weight of the bulb: 19 tonnes
* Sail surface area: 325 m2 upwind, 750 m2 downwind
* Crew: 17

Winning IACC yachts and teams

:"For a complete list of IACC yachts, see List of IACC yachts"

America's Cup

* 2007 America's Cup Winner - Alinghi SUI-100 (defender), Switzerland
* 2003 America's Cup Winner - Alinghi SUI-64 (challenger), Switzerland
* 2000 America's Cup Winner - Black Magic NZL-60 (defender), Team New Zealand, New Zealand)
* 1995 America's Cup Winner - Black Magic NZL 32 (challenger), Team New Zealand, (New Zealand)
* 1992 America's Cup Winner - USA-23 (defender), America³, (United States)

Louis Vuitton Cup

* 2007 Louis Vuitton Cup Winner - Emirates Team New Zealand NZL-92, New Zealand
* 2006 Louis Vuitton America's Cup Champion - Emirates Team New Zealand, New Zealand
* 2005 Louis Vuitton America's Cup Champion - Alinghi, Switzerland
* 2004 Louis Vuitton America's Cup Champion - Team New Zealand, New Zealand

Umpire Signaling System (“USS”)

The 2007 America’s Cup saw the introduction of the ‘’Umpire Signaling System’’ (USS) which allowed the Umpires to notify the two boats regarding their position in relation to each other when overtaking and their position relating to a mark of the course when in close proximity of the mark.

On both the defender and the challenger there was a display unit with three LED lights coloured green, amber and white respectively.

* GREEN lamp: ZONE ENTRY. Status ‘On’ indicates that the leading yacht has entered a zone of two or three boat lengths from the mark.
* AMBER lamp: OVERLAP. Status ‘On’ indicates that the bow of the overtaking yacht is overlapping the stern of the leading yacht and there is no restriction on the leeward yacht to steer a direct course for the next mark. The leeward yacht may point higher than the direct course to the next mark causing the windward yacht to either tack or sail higher than needed to the next mark.
* WHITE lamp: RULE 17.1. Status ‘On’ indicates that the depth of the overlap has increased to the point where the yacht to leeward must now steer a proper course to the mark and hence cannot point higher and force the overtaking yacht to either tack or sail a higher course to the next mark.

The rules of racing define what tactics/maneuvers are permissible when a yacht nears a mark and also when a trailing yacht starts to overtake the boat in front. The purpose of the "USS" is to remove doubt and associated protests caused by competitors having differing opinions of either their positions relative to each other or their distance from marks and then performing tactical maneuvers prohibited by the racing rules.

The system was developed by Pilotfish Networks AB.

The Formula

Formula: [ [http://www.americascup.com/multimedia/docs/2004/08/1092062211_accv5.pdf America’s Cup Class Rule Version 5.0] (from the America's Cup homepage)]

$frac\{L\; +\; 1.25\; imes\; sqrt\{S\}\; -\; 9.8\; imes\; sqrt\; [3]\; \{DSP\{0.686\}\; leq\; 24.000\; ,\; metres$

* DSP: displacement in cubic metres;
* L: rated length in metres;
* S: rated sail area in square metres;

The Future of the IACC

Immediately after the conclusion of the 2007 America's Cup, Brad Butterworth officially announced on behalf of Alinghi and America's Cup Management that a new design of boat would be sailed in the next edition of the America's Cup. The feeling was that the existing IACC rule had evolved as far as was practical and that in the spirit of the America's Cup, a new design challenge was needed. The new design will be longer, require more crew, require greater athleticism to sail and able to race in wind speeds up to 30 knots.

Due to the timescales required to finalize the design rules and build boats to the new rule, the existing Version 5 IACC boats will be used for the initial series of regattas leading up to the next America's Cup.

As at July 2007 it is not known if this new class of boat will be seen as yet another step in design and retain the name "International America's Cup Class" or will have a completely new name.

ee also

* List of America's Cup Class Yachts
* Louis Vuitton Cup

References