Following many months of work and consultation with designers, sailors, teams, and the America’s Cup community, Version Five of the America’s Cup Class Rule has been published. The result is boats that are lighter, quicker, more responsive and exciting, for sailors and spectators alike.

Version Five of the America’s Cup Class Rule makes a number of small, significant changes with a view to ‘turbo-charging’ the boats for the Mediterranean venue of the 32nd America’s Cup. The goal was to make America’s Cup racing closer, more vibrant and compelling, and increase the possibility of place changes downwind.

Work on a new draft of the Class Rule began nearly immediately following Alinghi’s victory in the 31st America’s Cup in March 2003. The parties responsible for the America’s Cup Class Rule are the Defender, the Société Nautique de Genève, the Challenger of Record, the Golden Gate Yacht Club, and the event authority, AC Management, represented by the Class Technical Director, Ken McAlpine.

Since 1992, the America’s Cup Class (ACC) has been the type of boat used for America’s Cup competition. At the end of each America’s Cup cycle, modifications and adjustments to the Class Rule are made in anticipation of its use for the following America’s Cup.

The intention of the America’s Cup Class Rule is to produce "wholesome, fast and manoeuvrable day sailing monohulls of similar performance intended for spectacular match racing in a wide wind range."

With the announcement of Valencia, Spain as the host city for the 32nd America’s Cup, the parties felt some small, yet significant changes were appropriate. Among the developments:
- A drop of one tonne in maximum allowable displacement
- An increase in maximum allowable draft of 100mm
- An increase in allowable downwind sail area of up to 8%
- An increase in working crew, from 16 to 17
- A general narrowing of permissible design parameters.

The drop in displacement, and increase in draft, coupled with the increase in downwind sail area, should make for much more lively performance off the wind, and increase passing opportunities on the runs. The increase in crew will help the sailors tackle that extra horsepower, while a narrowing of design parameters is intended to keep the racing close.

Boats measured to Version Four of the ACC Rule for the last America’s Cup will be permitted to sail in the 2004 pre-regattas. By 2005, Version Five of the ACC Rule comes into force. For older boats to comply some simple modifications will be required to bring the hulls back into class. The biggest part of this will entail hanging the bulb (with 1000kg of lead removed) 100mm lower. This will give an ACC yacht similar stability to the old configuration, and the same speed upwind.

But, with up to 8% more sail area downwind, a longer spinnaker pole, and 4% less displacement, the new rule will make for a more interesting boat downwind; one that will accelerate better, respond to gusts more quickly, and ultimately sail faster through the water.

AC Management has also been working diligently with the Defender and Challenger of Record to produce the "Terms of Challenge", a document outlined in the America’s Cup Protocol that defines the rights and obligations of all participants. The issuance of the document has been postponed to a later date "by agreement between the Challenger of Record and the Defender".