ORC Multihulls

Using the experience of over 30 years of development of the ORC rating systems for the monohulls through the ORC International and ORC Club certificates, and in the last several years the widely used ORC Superyacht rating rule, ORC now offers the ORC Multihull rating system for any type of catamaran or trimaran.
The measuring processes are the same as those of monohulls. The geometry of the hulls, superstructure, and appendages are captured in the hull offset file, which can be based on physical scanning or verified designer CAD files. The Offset file format accommodates a variety of different appendage types, such as curved foils or retractable boards. Rig measurements also follow the established monohull principles recognising also multiple foretriangles that are typical for multihulls. Sail measurements follow the World Sailing Equipment Rules of Sailing (ERS). Additionally, propeller measurements are taken also following already established procedures and protocols. The detailed ORCmh Rules and VPP Documentation will be published in due course.

Just as with any other ORC certificate, ORCmh certificates provide a range of ratings, expressed as Time Allowances in s/NM for different wind conditions in the range of 6 – 20 knots of true wind speed for a complete variety of wind angles.

Additionally, simple scoring options with single number Time on Time or Time on Distance coefficients are given also for the Windward/Leeward and All-purpose course model. Using a complete table of time allowances for different wind speeds and angles a custom single number scoring may be calculated for each specific race using historical wind data or weather forecast prior to the race.

During this development phase, ORCmh certificates will be issued by the ORC Central Rating Office. This will be extended to the National Rating Offices as the system further evolves.

For any inquiries about ORCmh or requests for a test certificate, please email mh@orc.org