ORC

While racing dissimilar boats against each other, the ORC system provides handicap ratings based on measurements of the boat, sails, mast, hull, keel and rudder, etc. Using the ORC VPP (Velocity Prediction Program), this data is used to calculate the theoretical speed of the boat in given wind conditions, and this is used to calculate the handicap ratings that will be used by race organizers to score the race.

To apply for the most basic level ORC Club certificate, there is only the most basic information needed: boat type, size (eg, length, beam and draft), keel type, rig dimensions (if known), and crew weight. Sources of this data may be from builder specifications, class rules, etc., as well as from a measurer. Sail dimension data, however, is required to be from a measurer or sailmaker to ensure accuracy, and this includes dimensions for the Mainsail, largest Headsail and largest Spinnaker, in addition to any Flying Headsails (those not attached to the headstay and <75% in midgirth/foot length ratio) and Code 0 spinnakers (75-85% midgirth ratio).

Sailmakers and measurers have now a new online process to enter sail measurement data.

For ORCi certificates, all data must be sourced from a certified measurer, and will include verification of an approved offset file of the boat used to describe the hull and its appendages, measurements of the rig, the freeboards and an inclination of the boat to determine stability.

If you’re interested in measurement, contact Chief Measurer Chris Tutmark (offshore@ussailing.org) for the contact information of a measurer near you.

If your boat is among the ORC One Design class boats found here, and it is in one design class trim, you may apply for an ORC One Design certificate with US Sailing.

Because it is not an approved One Design class by World Sailing, which requires strict compliance to published class rules and meets uniformity standards in design and construction. Without meeting these standards ORC cannot be assured all boats of this type have the same dimensions within reasonable and measurable tolerances and therefore perform to the same ratings. In some circumstances US Sailing will work with class authorities to determine a baseline set of dimensions to use for unmeasured ORC Club certificates.

It’s better to have an ORCi certificate because it gives your boat the most accurate rating, whereas most Club certificates may have un-measured assumed data that may not be accurate: the policy of ORC rating offices is to use data that is least favorable to the rating when there is doubt. Regardless, ratings from either certificate type are compatible for ORC scoring. Note that some races and regattas may require some faster entries to require ORCi certificates (for example, the Chicago-Mac race for boats faster than 515 GPH and in the Long Island Sound and Newport area for boats faster than 560 GPH).

The US Sailing application is located lower on this page under the Application section. Please read through application instructions listed below prior to applying. Also, remember to specify what race you need the certificate and its dates.

Yes, this is necessary because the ORC VPP improves every year to give more fair and accurate ratings, and thus ratings generated from one year’s VPP cannot be used to race against ratings generated from another year’s VPP.

Because the VPP has been upgraded and the new ratings represent the latest in VPP science from research conducted by the ORC International Technical Committee (ITC). Regardless of individual boat rating changes, it is ORC policy to try to keep these changes within about 0.5% for the over 1200 design types in the over 2500 boats rated in the ORCi database. And when comparing ratings always remember to use a competitor’s boat with the same year rating to gauge if there has been any change with the new year.

Because in order to take full advantage of the VPP to accurately model boat performance for a wide variety of boat types to get accurate and fair ratings, the predicted wind conditions during the race are needed to generate these ratings. In the US race managers also prefer to have pre-selected course models to choose from their options so that scratch sheets and scoring can be easily handled by web-based scoring software. Ratings shown on ORC certificates allows this scoring software to easily retrieve this data for use in scoring by simply entering a certificate reference number.

Yes, through use of the online web portal called ORC Sailor Services. With a free registration at Sailor Services, the user can access >150K measurement records including all ORC certificates issued since 2009. With the online search tool several features made accessible: certificate copies, their measurement data, use of an online editing tool to run what-if scenarios to examine rating effects in test certificates, populating online scratch sheets for time allowance tables, and obtaining polar performance data in graphic, tabular and digital formats in an ORC Speed Guide.

For advanced users even the ORC VPP is also available for purchase and download at ORC Software Downloads.

By use of a Time Allowance table that calculates time owed among the class entries for time (for Time-on-Time ratings) or distance (for Time-on-Distance ratings) sailed on the race course. This can be generated online by using the Scratch Sheet tool found at Sailor Services, either by yourself or as provided by the Race Committee.

Yes: all Headsails set Flying (HSF’s, also sometimes called LRH’s) in a boat’s active sail inventory must be measured as Headsails and declared on their certificate. These are sails that are not attached to the headstay. Sails that are larger than 75% mid-girth to foot length ratio are Spinnakers, and they are often called Code 0’s if they are between 75-85%. These sails must be measured as Spinnakers and all must be declared if they are in a boat’s inventory while racing.

Some Cruising classes limit the use of these sails, so make sure to check with your local authority on their rules and guidelines.

Any yacht may get a Roller Furler credit if they race with only one Headsail throughout the range of racing conditions and do not change sails. Some local authorities may amend this by allowing a heavy weather jib in the inventory of Cruising class entries.

The IMS rules give a description of what characteristics of the boat are needed to comply with the Cruiser/Racer designation, which for some yachts confers a small rating credit. The list of this criteria is in an appendix of the IMS rules and can be found here.

Crew Weight is one because it affects a boat’s predicted upwind performance. The greater the crew weight the faster the rated upwind speed because the VPP places that crew where it will have the most advantageous affect on performance – i.e, on the rail in breezy conditions, and to leeward in light air. There is a default crew weight that is used when no declared crew weight is made. Double Handed certificates use a default crew weight of 170 kg, but this can be changed to a declared value.

Once a valid certificate is issued by US Sailing, it remains in force until an amendment may be made to change the configuration of the boat. If this is desired, contact US Sailing with that change and an amended certificate will be issued that will supercede the validity of the previous certificate.

An exception is made when a boat may also want to have a valid Double Handed and/or Non-Spinnaker certificate: these may have their own configuration values for their own validity besides that shown on a Standard certificate.

Yes: Age Allowance is a credit for age of 0.0325% of ratings increase for each year from Age or Series Date to the current rule year up to maximum of 15 years (0.4875%).

There is also a Dynamic Allowance (DA) credit representing the dynamic behavior of a boat taking into account performance in unsteady states (i.e. while tacking) calculated on the basis of: Upwind Sail Area/Volume ratio, Upwind Sail Area/Wetted Surface ratio, Downwind Sail Area/Volume ratio, Downwind Sail Area/Wetted Surface ratio and Length/Volume ratio.

DA is applied to the ratings of all Cruiser/Racers, as well as any Performance boats with a Series Date older than 30 years.