The Two Main Qualifying Rules of Ocean Racing
As I commented in the previous article in gaceta náutica, the search for the «hole in the formula» was always the design pattern capable of making the most of the advantages of the rules to produce a faster yacht than what the numbers say. The two main qualifying rules in use until the 1960s on both sides of the Atlantic were the American CCA (Cruising Club of America) rule and the European RORC (Royal Ocean Racing Club) rule.
The Birth of the IOR
The growing popularity of international ocean racing events, such as the Admiral’s Cup and the Southern Cross Cup, and the revival of level qualification for the various ‘Toncups’, combined to push the two rules towards the need for a single international rule, and the IOR was born. It started with a lot of momentum but in time the rules began to be continually modified to control extreme designs and rigs. Modifications were so rapid that sailing yachts in production were becoming obsolete before they were launched or even before their moulds were finished.
Prolific Innovation and the Yawl Rig
His influence on yacht design during this period was prolific and full of innovation, and saw everything from magnificent to aberrant yachts designed to his parameters. The yawl rig, a two-masted, small mizzen mast, aft of the tiller, gained many followers due to the advantage granted by the compensation formulas of the time. It received a benefit of 4% of its surface area, as its propulsive inferiority was estimated at that percentage. An extra attraction of rigging a yacht as a yawl is the franchise to set a sail between masts of any size desired without receiving any time surcharge. All the other advantages of subdividing the sails to suit the conditions were only additional, as it always was, then and is now, the important thing is to have the lowest possible rating.
The Ketch Rig and the 12% Discount
The ketch rig has the mizzen mast set forward of the rudder and has a larger sail area than the yawl, the 12% discount on the ketch is more significant because of the lower efficiency allowed.
The larger the mizzen area, the greater the trade-off in these two-masted boats, given their lower overall rig height ratio and the lower their upwind efficiency compared to single-masted yachts.
Unusual Rigs and the «Hole in the Formula»
This concept generated unusual rigs, such as Jerry Milgram’s (USA) outlandish 38-foot ketch-rigged «Cascade» with no headsails. She was only 21 feet IOR (less than a half-ton). She had an arbitrary 10% penalty in the 1973 SORC rankings, but still won three of the races in the series. The design took advantage of the hole in the formula by transforming the 75 m2 of sail with the addition of the interstay into a genoa sail but measuring only 28 m2 of total sail area. But Cascade still managed to maintain a reasonably favourable rating, by the addition of a small jib at the bow (on a Star class yacht), and raced with some distinction until 1983. Cascade was hated by the entire fleet who scoffed at her hideous looks and damned low rating. The gaps in sail measurement were again demonstrated to even greater effect 13 years after CASCADE by the ketch rigs employed on three Farr-designed maxi-yachts in the 1989-90 Whitbread Round the World Yacht Race, a concept that was taken even further in the 1993-94 event where the mizzen rigs got bigger and bigger.
Disliked Rigs and the Evolution of Yacht Design
As is evident, today, two-masted cruising yachts have disappeared, except in the classic boats where the focus is on preserving the traditional rigs. There are many reasons why yachts rigged as single-masted sloops are the kings of racing today, but an important and disqualifying one is that windward-leeward racing is becoming increasingly popular, with upwind and downwind and no chance for a two-masted yacht.