The IRC Rating Authority has published a major rewrite of its Measurement Manual, providing more detailed guidance on yacht weighing, hulls, appendages, rigs and sails ahead of the 2027 racing season. The update is relevant to Irish owners competing under IRC, particularly those arranging measurements, modifying their boats or applying for Endorsed certificates.

Published on 12 November, the extensively revised Manual aims to make measurements more accurate, consistent and repeatable across the wide range of racing yachts using IRC internationally. The Rating Authority says reliable measurements underpin confidence in individual certificates and fair competition.

Expanded Guidance on Weighing

One of the principal changes is expanded guidance on weighing boats. It covers the condition in which a yacht should be measured, selecting and calibrating load cells, alternative weighing methods and the importance of single-point lifting.

The Manual also stresses the need to record the boat's condition accurately at the time of measurement so the results can be understood and reproduced.

Other updated sections cover hulls, appendages, rigs and sails, with additional guidance on interceptors, lifting appendages, twin rudders, unusual rig configurations, sail corner points and leech hollows. Quick-reference appendices address specialist measurements, including bulb weight and list angle.

Preparing for the 2027 IRC Season

The revised document incorporates changes taking effect under the 2027 IRC Rule. As Afloat reported when the 2027 Rule was published, the changes largely clarify existing requirements rather than introduce sweeping rating revisions.

The release also follows the publication of updated IRC race management guidelines for 2027, which address matters including certificate deadlines, equipment inspection and scoring.

For Irish cruiser racers, accurate measurement remains particularly important as clubs and owners assess handicap arrangements. Afloat has previously examined the differences between IRC and ORC, while its coverage of 2026 IRC certificate applications highlighted the need for owners to review their boat data and declare changes.

The IRC Rating Authority encourages owners planning measurement work, modifications or an Endorsed certificate to consult the revised Manual before beginning and to contact their local IRC Rule Authority where necessary.

The updated IRC Measurement Manual and supporting resources are available on the official IRC website, along with the Rating Authority's announcement.