Vincent Riou’s PRB rounding the Fastnet Rock - Rolex Fasnet Race 2011
In the Royal Ocean Racing Club's prestigious Rolex Fastnet Race in 2013 competitors will have to undertake enough races to qualify the skipper and crew for the Race. Most importantly,the competitors whilst racing will have to ensure safety gear, provisions and logistics are all in order.
However, two administrative items to tick off on their long 'To Do' lists will be having a current Spinlock IRC rating certificate, and the stability information required by RORC to ensure the boat is suitable to take part in the 600 mile offshore race starting on Sunday 11 August. For these, owners will be seeking the services of either the UK-based RORC Rating Office or their French counterpart, UNCL in Paris.
Most sailors will be familiar with the IRC time corrector (TCC) and measurements on a rating certificate, but have you wondered what the 'Stix' and 'AVS' numbers mean? They are not related to the boat's rating or performance, but her stability and seaworthiness, and are calculated from an International Standard. The Rating Office in Lymington, Hampshire, is the technical branch of the RORC and not only administers the international Spinlock IRC rating rule but is also responsible for checking and applying the Stix and AVS stability information on IRC certificates for boats around the world.
Say 'international stability index' to most people and their eyes will glaze over. The full details of how the Stix and AVS values are calculated are too technical for the majority but, in simple terms, higher values reflect a more 'seaworthy' boat. Considering the safety of boats and crews is of course high priority for race organisers and for many events, including the demanding Rolex Fastnet Race, yachts must comply with minimum safety and stability requirements to be able to compete.
Sometimes, it may appear to some that the extra information demanded and the strict limits imposed are unnecessary hurdles to overcome, but competitors should remember that race organisers, the Rating Office and UNCL are simply concerned with the well-being of skippers, their crews and their boats.
You can read more information about Stix and AVS, and see the IRC Rating Authority's list of designs and stability values, on the IRC website
Rolex Fastnet Race website