Glyn Locke and Myles Mence have been racing their Viper very succesfuly on the Solent since last summer. They have had their boat weighed and measured under both the RYA Sportsboat handicap rule and the RORC "IRC" rule. The boat has been competitive under both rules. For details on the handicap, please refer to "Handicap Information" section of the website  http://www.viper640.org/the-viper-640/handicap-information