The COA's performance based HKPN system is a development of the Royal Yachting Association's Portsmouth Yardstick System (PYS) and doesn't requires any boat measurements to be taken. It is a computer based, statistical analysis system, which produces a time correction factor, or performance number (PN) for each yacht, based on the yacht's racing performance relative to its competitors.

An initial PN is allocated to a boat upon application and an adjustment is calculated after every qualifying race. Then, subject to its approval by the COA Ratings Committee, a new performance number is issued after every fourth qualifying race.

In order to avoid adjustments that are due to non-typical poor performances, the system calculates a limiting time for each race, based on the fleet's performance. If a yacht's elapsed time in any race is greater than the calculated limiting time, then the yacht's performance in that race is considered as non-typical and no adjustment is made. Should a boat's PN appear to be incorrect, the owner may request a review, by making a written application to the COA Ratings Committee. Each request must be accompanied by valid reasons for the review.

This is a versatile system, which can allow cruising boats with less experienced crews to race competitively against their seasoned racing counterparts. It can also provide finely tuned ratings for the more experienced yachtsmen. However, since it is a performance based system, which makes allowances for the less experienced crews, those wishing to compete on a more evenly matched basis will want to race under IRC or the Sports Boat Rule (SBR), which are based on the boat's capability rather than the crew's.

An HKPN handicap  may be obtained by completing and returning the appropriate HKPN Application Form which may be downloaded from our website or obtained from the COA office. The initial handicap, or performance number, will normally be issued within ten to fourteen days. HKPNs are supplied free of charge to COA members but there is a HK$100 fee for non-members.