The word ‘‘yacht’’ is from the Dutch, and recreational sailing was practised by Dutch nobility early in the seventeenth century, if not before. King Charles II brought the term to England, the first recorded yacht race being between himself and the Duke of York in 1661 (Johnson, 1989). Sailing has since become a very popular leisure activity, pursued on almost every stretch of water in the developed world from small reservoirs to the open ocean. However, taking the UK as an example, the number of people involved each year is estimated by the governing body to be around 500,000 (about 1.5% of the active population.) It is also a highly competitive sport, first figuring in the Olympic Games in 1900. It is pursued in craft of every size from small single-handed dinghies and sailboards (windsurfers), to large fixed-keel yachts usually with multi-person crews either racing on short courses close to the shore, as in the America’s Cup, or sailing across oceans and around the world (where the extreme of achievement is, despite the boat’s size, to do the whole thing single-handed). The sport therefore embraces every level of sailor, from occasional recreational sports people to elite international competitors, many of the latter nowadays sailing professionally. At each level it is also technically complex: hull and sail design, wind and sea state, tactics and teamwork, and the physical characteristics, physiological capacities, and nutritional status of the sailors all interact with their sheer skill to influence performance. A further complication is that the roles of different crew-members, even on a single boat, vary greatly: the winchmen on an America’s Cup yacht face totally different demands, both physical and mental, from those confronting the helmsman of the same boat, while the dinghy sailor and the boardsailor are each doing almost entirely different things, both from one another and from the winchmen and helsman on the yacht. There is surely no other sport that embodies such diversity. The papers in this issue reflect some, but by no means all, of the possible range. Inevitably, they reflect also the relative intensities of research activity, which in turn are loosely related to the number of people who participate in the particular sailing activity concerned. About half the contributions in this special issue on sailing physiology are concerned with the ‘‘hiking’’ of small dinghies, in which the sailor leans out over the water to balance the boat against the wind. (There is no equivalent in larger yachts, because these have heavy keels to keep them more or less upright and the most crews may do is sit on the ‘‘uphill’’ side of the boat, adding their fractional leverage to that of the keel.) The substantial physiological challenge of hiking is considered first by Spurway, who reviews much of the earlier research, as well as describing some recent studies of his own. He maintains that the physiological situation during hiking is dominated by sustainedly restricted blood flow in the muscles bearing the main anti-gravity load of this position – principally the quadriceps. Succeeding papers, by Vangalakoudi et al. and Easton et al., essentially accept this view. A previously published paper by Castagna and Brisswalter 2007 also concur with Spurway’s account of hiking but evaluates the extra oxygen demand naturally (and quite uncontroversially) incurred by frequent ‘‘tacking’’, which is the process of turning the boat through the wind until it blows onto the other side, thus requiring the sailor(s) also to change sides. Cunningham and Hale, however, regard the physical activity of elite dinghy sailors, even during hiking itself, as far too dynamic to be described in Spurway’s terms. Of course, the issue would be simply resolved by detailed physiological monitoring of elite performers during competition but this, unsurprisingly, has never been possible. The approaches have therefore to be indirect, which is the main reason for the continuing controversy. We should therefore spell it out further. Spurway, a lifelong sailor and coach, who himself in earlier years finished at or near the top of several national dinghy championships in the UK, conducted his formative experiments on hiking physiology in conjunction with Vogiatzis, an even higherachieving Greek sailor. They were jointly convinced that significant changes of thigh position and loading, at a frequency of several times per minute, do not occur, and indeed would be so disruptive as to be physically impossible for a competitor whose Journal of Sports Sciences, August 2007; 25(10): 1073 – 1075