VPRS is a new rating system for ballasted monohull yachts.
It is based on a mathematical model that uses a range of well-established analytical and empirical techniques to estimate the resistance of the hull and the power available from the sails, based upon a set of hull and sail measurements. These are used to calculate the speed potential of a boat.
The rating is given in the form of a Time Correction Coefficient (TCC).
The design of the model will not be made public so as to discourage owners or designers from attempting to exploit the constraints of the model in order to gain unfair advantage.
Although the model has in part been designed to ensure that ratings are in line with observed performance, no subjective adjustments are made to the calculated rating. The model may be changed from time to time in the light of experience, but any such changes will be applied to all boats.
The necessary measurements are normally supplied by boat owners. We reserve the right to compare these with our database of yachts already rated and, where significant differences exist, to substitute standard hull measurements - unless the owner can produce suitable evidence to support their own measurements. We can provide assistance with measuring if required.
Please note that VPRS is still under development - in association with Poole Yacht Racing Association (PYRA). It is hoped that system design will be complete by the end of March 2010, so that VPRS can be evaluated as a possible alternative to PHHS during the 2010 season.
It would be greatly appreciated if all PYRA members could check the details of their boat and advise any errors or changes.
A list of the measurements required and a guide to making them is on the measurements page.
During the 2010 season, race results calculated using VPRS will be published on both the PYRA site and here on the results page.
Feedback and new applications for rating are welcome via the contact page.
