The America’s Cup Regatta is now sailed in America’s
Cup Class yachts, which were specifically developed
for use in America's Cup competition. Required to
have 16 crew, they were first used in San Diego
in 1992 for the 28th America’s Cup Regatta.
As it said in the AC Class Rules, "the America's
Cup Class is intended to produce wholesome day sailing
mono hulls of similar performance while fostering
design developments that will flow through to the
mainstream of yachting; and for yachts that are
raced “around the buoys” with tenders present, as
opposed to offshore in high winds and rough seas
with or without tenders.”
The ACC Rules set stringent design criteria and
establish a design formula which forces designers
to balance length against sail area and displacement.
The variable geometry equation can be compared to
a box into which the boat shall fit in, but inside
which the parameters may be modified infinitely
:
L is the rated length in
metres.
S is the sail area, the sum of the foretriangle
area and the mainsail area.
DSP is the displacement in cubic metres
The problem consists of finding the best compromise
beetween these three parameters in order to design
and build the fastest ACC Yacht.
Average speed of ACC yachts from one edition to
the next has progressed by something in the order
of 3%, around 3/10th of a knots (0,54 Km/h) and, in
order to won, you have to be 1% ahead of boats of
the same generation.
All competing yachts are subject to very stringent
inspection and measurement regimes, both during construction
and prior to and during the America’s Cup Regatta.
The ACC Rules are administered by a technical director
and his staff who undertake inspections and issue
interpretations of the ACC Rules from time to time.
Each yacht built receives a consecutive class number.
Up until the end of the 2000 America’s Cup Regatta,
62 America’s Cup Class yachts had been numbered since
1990 and 20 new America’s Cup Class yachts were built
for the 31st America’s Cup Regatta, with sail numbers
63 to 82 being consecutively issued for each new yacht.
When yachts change ownership, the sail number remains
with the yacht, with only the national letters being
changed if the new owner is of a different nationality.
The class insignia is the silhouette of the America’s
Cup and appears on the mainsail.
A
BRIEF HISTORY
America
At the beginning
of the Cup, restrictions imposed on the yachts had
caused a great deal of variation in design. While
the handicap of a 3000-mile ocean passage placed
definite limitations on the challenger, all that
was required of the defender was that she should
hold together for her first season-a short-lived
blaze of glory.
In 1906 and 1907 a series of conferences were held,
attended by representatives of 13 countries, including
the three national classification societies then
in existence. Following these conferences the International
Yacht Racing Union introduced the first international
rules for yacht measurement.
1934 - Ranger vs
Endeavour
During discussions
leading up to the 1930 Cup races, which were to
be held for the first time between the great J-Class
yachts, it was decided that in the interests of
the event, all vessels talking part in future Cup
races would be built in accordance with same Rules.
The revival of the contest after the Second World
Warwas brought about by another alteration to the
Deed of Gift - this time by the New York Supreme
Court . This amendment reduced the waterline length
to 44 feet and welcomed a new type of competitor
to the races, the smaller 12-metre boats. The restriction
that vessels had to sail across the Atlantic on
their own bottoms had to be dropped.
The need for a new class prescription arose from
two developments. The first was a growing disenchantment
with the cumbersome 12-metre class, which had been
used in the Cup since the first post-War event in
1958. The 1988 "mismatch" between the giant New
Zealand sloop KZ1 and San Diego Yacht Club's catamaran
defender also influenced Cup players, who determined
to ensure that in future there would be a level
playing field, and a new, more exciting class of
yacht.
This rule was established over a period of time
during 1989 and 1990, with an informal group of
designers sharing ideas, systemising the key parameters,
and establishing new formula.
