"It is the spirit and intent of the rule to
promote the racing of seaworthy offshore racing yachts of various
designs, types and construction on a fair and equitable basis."
Thus began the introduction of the IOR Rule. It was an ambitious
aim. For over a century yachting authorities on both sides of the
Atlantic had tried to devise a rule that fairly equated yachts of
different sizes and speeds.
The ancestor of modern rules was the Seawanhaka
Rule of 1883. This evolved into the Universal Rule of Nathaniel
Herreshoff which was in use before the First World War but was known
and used only in the US. Similar developments were going on in
England and the Boat Racing Association Rule of 1912 showed strong
similarities to the rule ultimately adopted for the Fastnet Race by
the Ocean Racing Club in the late 1920’s. The International Rule,
promulgated for the first time in 1907 by the newly formed IYRU was
used at the times in Europe and Asia, and for the early Olympics at
several level classes. The British used girth stations to determine
length, while the American Rule used buttock length. In 1928 the
Cruising Club of America used the British Rule with minor changes,
but the use of this rule on both sides of the Atlantic was
short-lived. In 1932 the CCA produced its own rule which tended to
be type-forming, containing, as it did, a number of "base"
dimensions, and penalties provided when differences from the base
boat occurred. The measurement of stability was a novel thing in CCA
When ocean racing resumed
after the Second World War the rules tended to diverge, in that the
CCA Rule was adapted from time to time to encourage owners to build
the sort of dual-purpose cruiser/racer that the club thought
desirable. The Royal Ocean Racing Club was less restrictive towards
the development of the pure racing boat, such as "Myth of Malham."
The CCA was adopted only in the US, while the RORC Rule had been
adopted by many cruiser/racers. In the Med and a few other countries
the RORC Rule was extended to smaller boats, and called the “C”
But the demand for a truly International racing rule really started
when some trophies and events were created on both sided of the
Atlantic that encouraged international team participation. These
included the Onion Patch series and later the SORC in the US, where
the CCA was used, and the Admiral's Cup, where the RORC rule was
By 1961 it was clear that there were two very different rules, the
RORC Rule for Europe and the Antipodes and the CCA Rule for North
and South America. This situation was not to the liking of a number
of European sailors who gathered in Bremen on 5 June 1961 at the
suggestion of Rolf Schmidt of Germany.
Later the same year delegates from four countries met in London and
decided to form the Offshore Rules Coordinating Committee. This
committee worked throughout the 1960’s and the original four
countries (Germany, Great Britain, Sweden and the United States)
were joined by Denmark, Norway, Finland, Holland, France, Italy,
Australia, Canada and Belgium.
The ORCC was chaired throughout by Buster de Guingand. The Committee
concentrated on trying to align the two rules in matters that were
not of fundamental importance, such as the details of sail
Beginnings of an International Rule
In 1965 there were rumors
that the 1968 Olympic Games might include an offshore racing class
and in 1966 the International Yacht Racing Union asked the RORC and
the CCA to try to frame one international rule. Both clubs agreed,
and at the April 1967 meeting of the ORCC an International Technical
Committee was established. Olin Stephens was the chairman and the
other American representative was the designer Dick Carter. Europe
was represented by Gustav Plym of Sweden and Ricas van de Stadt of
Holland, and Paul Spens from England. The English measurers David
Fayle and Robin Glover completed the committee.
Between April 1967 and November 1968 the committee met on a number
of occasions and the ORCC considered the draft of a new
International Offshore Rule at its November 1968 meeting in London.
It was then unanimously agreed to recommend to all national
authorities that the Rule should become operative in the 1969
The set of measurements and the formulae for the length, the depths
and the freeboards were taken mostly from the RORC Rule, and were
finalized by Olin Stephens and Paul Spens. A Fortran program was
written, using punched cards that in these early times had to be
sent to a remote server. The USYRU was instrumental, with the help
of MIT, in setting up this impressive software development, where
the set of data entered could print out a certificate with a dot
matrix printer of the times.
In parallel during 1968 and 1969 a Special Regulations Committee was
established to carry out the same sort of process with special
regulations of different countries to accompany the measurement
rules, and set some standards for safety at sea on offshore racing
A constitution committee was also set up to prepare a constitution
for a new Council - this council was to control the Rule and was to
be formed with the sanction of IYRU.
Birth of ORC
On 1 November 1969 the
Offshore Rules Coordinating Committee held its final meeting and
approved the Constitution for the new Offshore Rating Council.
The Organization was revolving around the Rule and the computer
program able to calculate the many measurements entered, with
punched cards or tapes, and print the certificate on one or 2 pages.
Any National Authority could make use of the program, paying a
“levy” for every certificate issued.
The Council had from the beginning a close relationship with the
IYRU, whose President, Beppe Croce, was a Council member until 1981.
Even now the sitting ISAF President holds a seat in the ORC.
Initially there was some slight suspicion of the role of the new
Council, and its somewhat limited function was denoted by calling it
the "Offshore Rating Council."
By the mid-1970s the Council had shown that it had a secure place in
the control of level rating as well as rated yachts and special
regulations, so in 1976 the Council changed its title to "Offshore
Racing Council." The development of a common international rule had
taken thirteen meetings and eight years but all felt that the effort
was well worthwhile. The rule that emerged was based upon the CCA
approach to sail measurement and the RORC method of hull
measurement. The biggest problem in 1969, as it is to the present
day, is how to determine the vital L measurement under a system that
is based on the use of girth stations.
For the next three years the Council met at least twice a year and
the ITC even more often. The work of adding finishing touches to the
rule took the Council to San Francisco, La Rochelle and Portofino.
After 1975 the Council reduced the frequency of meetings to one a
year in London each November.
Birth of IOR
The IOR arrived just in time
to catch the boom in international racing represented by the growth
of the Admiral's Cup, the Southern Cross and the Onion Patch series.
The boom itself caused the serious problems that began to arise in
rule management in the mid-seventies. Intense international
competition and boat construction worldwide encouraged a bunch of
amateur designers to do their trial, and eventually find their way
to exploit the Rule to the full and so produce highly specialized
racing boats very fast for their rating. This was unpopular
particularly in the United States where many owners favored the
traditional compromise between cruiser and racer.
This policy was followed and was generally popular until the
mid-1980’s when another surge of development in technology of both
design and materials took place.
The Rule gave excellent racing to the new “custom” designs and still
accommodated the older yachts but the changes which would have been
required to make traditional cruiser/racers truly competitive with
this new generation of lighter yachts, so some Cruiser/Racer
protected Divisions had to be created to ensure participation at the
events, a policy that is continued with the current handicap rules.
David Edwards, Chairman of the Council from 1970 to 1978, and John
Roome after him, made a great contribution in preserving a delicate
balance between the interests, favoring generally rule changes to
protect the existing fleet against early obsolescence, but keeping
up a fair game at the top events. Rules were changed as loopholes
were exploited, but discussions were often harsh.
In this period of two decades the system expanded and prospered
worldwide, and with the advent of programmable calculators and later
personal computers, the IOR program became a sort of exercise all
designers and “expert” sailors of the times spent a lot of time
doing. Many thousands of boats were measured in a complex way by
expert measurers, and raced in many races all over the world at
various levels, IOR being the only recognized system in use. The
size of the fleets allowed the organization of individual Class
championships, and very competitive International Level Class
To keep a limit on boat sizes, IOR has always maintained a “top”
limit of 70 feet, even if the program and the formulae could give a
rating to any size. This gave event organizers an workable benchmark
limit for entries, and produced the concept of a Maxi class for
boats rating at or about this limit. With large budgets and owner
egos to match, the Maxi class soon became the focal point for design
development and a suitable home for an emerging class of
high-profile professional sailors.
The Maxi class later spurred the development of various sub-classes,
such as the Mini-Maxi’s, the Super Maxi’s, and most recently the
The IOR has been frozen in place with the 1993 version, but is still
operational and usable for any race or certification renewal anytime
- some IOR racing continues even now in Italy and Russia.
Advent of IMS
In 1985 the Council decided
to adopt the Measurement Handicap System used in the US, renaming it
the International Measurement System (IMS), as an alternative rule
to accommodate traditional yachts, while continuing to manage IOR
for the leading events and for the many other fleets which preferred
to continue under that Rule.
In 1989, a policy of rule stability was adopted with respect to the
IOR. This was strengthened in 1990 by removing the possibility of
designing new yachts to the Mark III A formula, which had originally
been introduced to promote dual-purpose boats. Also in 1989 certain
“exotic” materials were banned for IMS yachts and smaller IOR yachts
in order to keep costs down and reduce unrated performance
advantage. By 1990, IMS had become well established in various
countries - notably US, Netherlands, Finland, Germany and Australia
- and thereafter continued to grow steadily throughout the world.
Level rating classes –
the Ton Cups
The IOR Level Rating Classes
(Ton Classes) were popular at the leading edge of IOR racing until
keen racing owners gradually began to turn to IMS designs in the
early nineties. Ton Classes had originated with Jean Peytel's idea
to revive the old 6-Meter trophy, the One Ton Cup, for competition
without time allowance between yachts rating 22 feet under the RORC
Rule. The One Ton Class was followed in 1966 with the Half Ton Cup
and the Quarter Ton Cup in 1967, both on the initiative of the
Societe de Regates Rochelaises, and Pierre Chambonnet in particular.
In 1967 the Yacht Club Italiano started the Two Ton Cup and in 1974
the North American Yacht Racing Union presented the Jean Peytel
trophy for the Three Quarter Ton Cup at 24.5 feet IOR rating. In
1973 the clubs that started the original Ton Cups generously
presented the trophies and the right to administer the races to the
ORC. In 1984 the Two Ton Class was discontinued and the maximum
rating of the One Ton Class was raised to 30.55 feet. The One Ton
Class became very popular at this new maximum rating and in 1990,
following competitor demand, the Two Ton Class was re-introduced
with a maximum rating of 35.05 feet.
Following a two-year
development period in the early 1990’s for a new Grand Prix Rule,
the ORC inaugurated the International Level Class Rule (ILC Rule)
based on levels defined using the International Measurement System
(IMS). Under the ILC system, levels are set by "performance
envelope" limits, i.e., performance limits at 3 points of sail in 3
wind velocities ensuring close class racing on all courses.
The first ILC World Championship was held for the ILC 40 in Denmark
in 1995. In the years immediately following, the rules for the full
ILC family were developed, eventually including the ILC 25, 30, 40,
46 and ILC Maxi Classes. As the new classes emerged, they replaced
the corresponding IOR Ton classes, with the last ORC World
Championship under IOR being held in Quarter Tonners in 1996 and the
1 Ton Cup in Marseille in 1994. These classes eventually led to the
adoption of more flexible forms of the level class format, e.g., the
IMS 600 Class.
As the use of IMS in grand prix racing grew, it became necessary for
Council to take steps to protect the fleet for which IMS had
originally been developed by defining two divisions within IMS, the
Cruiser/Racer Division and the Racing Division, the distinction
being made on the basis the degree to which the features of a
yacht's build, outfit and accommodation suited cruising
considerations. The prescriptions for this were promulgated in 1993,
and are now contained in the IMS Rule, and are accounted for in
By the mid-1990’s the popularity of the IMS had grown to the degree
that the IOR was completely replaced, and by 1999 an IMS World
Championship was introduced with scoring based on time allowances.
Advent of ORC Club
With the popularity of IMS
came the inevitable pressure of competition at the highest level,
resulting in the sense that a simplified version of IMS should be
made available for the local racer at a modest cost. This concept
was developed during 1997 and was introduced the following year
under the name ORC Club.
The number of required measurements for ORC Club is reduced by the
use of a system of calculated default measurements that replace
measurements that would otherwise be required for a full IMS
Certificate. The system made it possible to calculate ORC Club
handicaps using the same Velocity Prediction Program as for the IMS,
but without the burden of a complex and expensive measurement
A fundamental benefit for this concept is that ORC Club yachts could
be raced and scored together with full IMS yachts and it is
therefore not necessary for race committees who wish to adopt ORC
Club racing to introduce a separate division; the Club-rated yachts
could simply be mixed together with existing IMS yachts and race for
the same prizes.
The popularity of ORC Club grew at such a pace that within four
years the number of Club yachts surpassed IMS yachts. Countries with
no previous IMS programs established Rating Offices for ORC Club and
the system began to be taken up also for sportboat racing.
Safety and Offshore
Throughout this time work
continued on the Offshore Special Regulations (OSR), the objective
being to improve the safety equipment and so far as possible to
standardize regulations in all countries. The 1979 Fastnet Race led
to demands to strengthen the Regulations as well as to encourage
increased stability in the yachts, and a special Council Meeting was
held in Barcelona in 1980 to ratify these rule changes. There were
also demands for a scantling rule to control the construction of
hulls and spars.
A Guide was eventually produced by the American Bureau of Shipping
in conjunction with the ITC, and plan approval was made mandatory
for yachts built after 1 January 1986 racing in Categories 0 and 1,
and other yachts racing Category 2.
The OSR are today used worldwide, occasionally modified for local
racing, and are also used for many simplified rules such as IRC in
France and the UK and PHRF in the US, but from 2001 they have passed
under the jurisdiction of ISAF. The core of the current ISO
standards also rely mostly on the requirements contained in the OSR.
Brief merger option
with ISAF, renaming of ORC
In 1997 negotiations were
initiated to agree a merger of ORC with the newly-renamed ISAF, and
the following year the ORC office was moved to the ISAF headquarters
in Southampton, where it remained until 2002 when the merger plans
were abandoned, there being too large a gulf between administering
to the interests the offshore constituency and those of one-design
classes. At the AGM in 2001 in Lisbon the ORC was supposed to be
ISAF’s newly constituted Offshore Committee, but instead just the
Special Regulations moved to within its jurisdiction.
With the success of ORC Club came additional countries administering
ORC programs and to provide for broader representation, the
eligibility for Members of Council was put on a new basis related to
the number of certificates issued annually. The expanded Council was
ultimately given a new name, the Offshore Racing Congress.
Recognition of growing interest in elite offshore racing led, in
2005, to the development and introduction of three new, grand prix,
fixed-formula classes to be raced without handicap: the ORC's GP 26,
GP 33 and GP 42, with design and building getting under way for the
inaugural 2006 season. Thusfar, the GP 42’s have enjoyed the best
success of these classes, with 15 boats built from 2006-2010, and
competitive class racing held in the 2007-2010 seasons in Europe,
including two seasons in the Audi MedCup. While not having any
organized class racing yet, GP 26’s continue to attract build
interest on four continents.
ORC International was started at the 2007 ORC Annual General Meeting
in Estoril. This represented the ITC’s major overhaul and
significant improvement to the ORC’s VPP and rating system, with
elimination of some of the poor typeforming qualities seen in the
old system. IMS would now be a measurement protocol only, used for
inputs to ORCi and ORC Club rating rules. All ORC Championships
would henceforth be run under the ORCi rule.
At the urging of ISAF, merger discussions were started in Feb 2010
with RORC to form a new company to manage ORC and IRC rating systems
as a single rule authority. These discussions are still ongoing.
In 2012 ORC agreed with US Sailing and the RORC Rating Office to
help develop the concept of a Universal Measurement System (UMS) in
which a “passport”, or complete characterization of a boat’s
measurement profile, would be possible to enable use in any
measurement rating system.
Also in 2012 ORC has agreed with the Offshore Racing Association in
the US to help administer the new High Performance Rule (HPR) that
is suited for modern high-performance designs. HPR will utilize
measurement standards consistent with IMS and the new UMS.
Technical milestones in the rating system:
- 1970: first IOR program listing
- 1983: first PC program for IOR
- 1986: first PC IMS program
- 1990: crew weight and stability index formulations
- 1993: New Rr introduced, double Division Regulations, DBOS
- 1995: carbon masts and asymmetric sails allowed. ILC concept
- 1997: Dynamic Allowance
- 1998: new Windage model, defaults for ORC Club
- 2000: new Rr regression & L formulation
- 2003: propeller strut fixed
- 2006: new aero model
- 2007: ORC system, new program, new data format
- 2012: new Rr formulation