From the insight and research of British designers Hugh Welbourn and Gordon Kay, experiments with DSS (Dynamic Stability Systems) foils began on monohulls in the early 2000s. In fact, Hugh Welbourn had already been on this track since the late 1990s and proposed to Ellen Macharthur that she experiment with these appendages on the Kingfisher, the boat in which she would participate in the 2000 Vendée Globe. The Briton declined the proposal, fearing too radical a technical solution for a project crucial to her career.
DSS were initially tasked with improving the boat’s righting moment and consequently performance. Later, as shapes and technology evolved, in addition to dealing with straightening, they began to look for lift, or so-called lift effect, which exponentially increased speeds.
Early appendages of this type consisted of a single horizontal, telescoping blade working downwind just at the beginning of the live work. Especially in the last 5 years, with the development of C- or L-shaped dinghies, there has been a gradual effort to increase vertical buoyancy as well, and numerous versions of DSS foils have emerged, differing from each other even according to the boat on which they were applied.
Except in a few cases, such as the Quant 23 released in 2014, most of the DSS appendages we have seen at work in recent years on monohulls are hybrid, that is, they favor both righting and lifting in a balanced way. The case of the Quant 23 is different: thanks to a lightweight and small design, it was possible to successfully apply C-shape drifts that enabled true full foiling, that is, the complete exit of the hull from the water. A phase that is now in full swing among Mini Transat prototypes, whose flight is more complex due to canting keel (canting keels) significantly bulkier and more powerful than seen on the small Quant.
THE “LANDING” OF DSS AMONG THE CRUISERS
Today, with the landing of foils on the IMOCAs, in the Mini class and among the Figaro, other designers are tackling this technology with increasingly spectacular results. The new frontier, however, seems to be cruising boats, and once again it is Gordon Kay’s Infiniti Yachts, with the new 56′, that is charting a new course: cruising on foils. From this point of view, DSS could really be a great upgrade for the cruising world, going on to improve a detail that is very dear to sailors who seek comfortable and quiet sailing: righting.
Less heeling equals more comfort, thus greater enjoyment of sailing, a perfect paradigm for the recreational world as well. Like all cutting-edge technologies, dynamic stability systems seek extreme limits in the racing world, only to find application with more proven versions on the cruising front.
The simplification of appendage handling systems may thus have reached a point where they are being offered to the general public, and potentially in the more or less near future we may see a cruising boat equipped with foils in large series production.