Published in the magazine Gaceta Nautica by Juan Jose Merayo of Incidence Sails Palma

The times of the IOR formula, in the 70’s and 80’s, were a lot of fun because new things were constantly emerging: designers, sailmakers, mast makers and non-professional enthusiasts were looking for ways to squeeze the formula to the maximum to achieve less measurement, sometimes at the cost of safety and on the verge of illegality.

The Blooper

The Blooper, the free sail of the IOR yacht measurement formula

Nowadays the boats are very similar and there is little room for novelties, at least for normal budgets. Millionaire yachts with sponsors and professional crew are another matter. The IOR boats used to carry gigantic headsails in relation to a small, narrow mainsail. The spinnakers would roll from one side to the other, sometimes ending up in a broach with consequences, because the spinnaker could not be compensated by such a small mainsail, and it is also true that the shape of the hull did not help to keep the course, a staysail or a light staysail quartered helped, but not enough in fresh winds. The leeward space was only partly covered by the small mainsail, so the indefatigable dynamic minds contrived to hoist a sail on the leeward side, and as it could not be another spinnaker, a genoa began to be hoisted. With use, a special Nylon sail was developed, lighter and more flexible, which was called a blooper (?). The luff was exaggeratedly negative in order to be able to measure like a genoa, displacing the greater surface of the sail outside the mainsail. Although the first intention was to increase surface area to produce greater speed, it turned out that it also provided balance to the uncontrolled roll.

The Role of the Blooper

The bloopers, also called shooters (?) helped to provide balance and also kept people busy, giving work to hands that were hitherto idle. As none of the three ends of the sail were fixed, the trick was to release halyard tack and sheet so that it flew away from the mainsail like a kite, all with the risk of collapse, flutter or other problems that would deflate it and it would fall into the water. The crew had to be attentive to quickly pick up halyard, because once in the water the sail was transformed into a fishing net, bringing the boat to a complete stop.

The blooper’s reputation was not very good, defined by some sailors as an «infernal, almost uncontrollable flying sail, which often ended up in the water. However, there was consensus on the role of the blooper in helping to stabilise the boat, as well as, in some cases, increasing speed, while still complying with the rules of the formula and above all not increasing the rating… it was FREE.

Forbidden the Blooper

Bloopers are forbidden in the current formulae, but in pre-1985 boats where they were part of the sail inventory, they can be used to compensate for spinnaker. Another issue that has always been the subject of discussion and modifications to the formulas that measure them is battens. As soon as ways of measuring the performance of ships appeared, batten lengths were of interest to the rule makers. It was obvious that the longer the battens, the more sail area for mainsails and jibs, so initially and until the IOR and CCA formulas (now used by the classics) the regulation was done by limiting the batten length. The sailmaker could design and manufacture the sail of any size he wanted but controlled by a batten size determined by the formula which were ridiculously small, so that the battening of the leeches at that time was non-existent. At the same time the popularity of catamarans carrying giant leeches with long battens (Chinese junks had been using long battens and lazy jacks for centuries) began to change minds and traditionalist rigidities, and cruising-only boats began to use long battened sails because the sails fundamentally flapped less and lasted longer. Finally, the appearance of the IMS formula in the mid 80’s cooked all these novelties and changed the concept by measuring the width of the sails and thus determining their surface area, independently of the length and quantity of the battens, as it was concluded that the length of the battens had no effect on the speed of the yacht, but rather the surface area of the sail. Speed comes from two things: the shape of the sail and its surface. Batten length does not really improve the shape of a new sail, it just makes an old sail look like new for longer. This is not something to penalise.