Measurement is a fundamental
part of any rating system. In order to have a boat's rating
calculated, the boat’s characteristics need to be defined by taking
the measurement of all parts that affect the boat's performance.
Boats shall be measured by official measurers as appointed by the National Sailing Authorities
and approved by the ORC. Use of ERS makes use of IMS easy for
measurers of other international classes, while for parts specific
to offshore boats and measurement principles in general, ORC
regularly organizes Measurers Conferences.
From Measurement to Rating
IMS is used by the rules described in the ORC Rating Systems to generate ORC International and ORC Club certificates. Both are fully compatible, with the only difference being that all data on an ORC International certificate has been taken from measurements defined by the IMS, while for ORC Club this data can be measured, declared by the owner (subject to verification by the Rating Authority) or obtained from any other source, including photos, drawings, and/or data from identical or similar boats. Since they have fully measured data, ORC International certificates are therefore more accurate than ORC Club.
Unless otherwise specified, measurements shall be taken and recorded to the nearest greater value as follows:
Boats shall be measured dry in light ship condition without crew, which as defined in details in IMS Rule E2. Items on board include:
Specifically excluded from the measurement trim are the following:
An easy explanation of lightship measurement trim would be that if the boat is rotated upside down, everything that falls out shall not be on board.
When IMS is used a boat is in compliance with its ORC certificate when:
All measurement data can be recorded and stored by freely