Windsurfing aside, many expert windsurfers will ride the same waves as surfers do (wind permitting). At one time referred to as "surfing's ginger haired cousin" by the sport's legendary champion, Robby Naish, windsurfing has long struggled to present a coherent image of the sport to outsiders. As a result of attempts to claim the word "windsurfer" as a trademark, participants have been encouraged to use different names to describe the sport, including "sailboarding" and "boardsailing". The term "windsurfing" has persisted as the accepted name for the sport, and the word "windsurfer" persists for both participants and equipment. Windsurfing is predominately undertaken
Activity coefficient anion respectively. More generally, the mean activity coefficient of a compound of formula AB is given by Single-ion activity coefficients can be calculated theoretically, for example by using the Debye–Hückel equation. The theoretical equation can be tested by combining the calculated single-ion activity coefficients to give mean values which can be compared to experimental values. The prevailing view that single ion activity coefficients are unmeasurable independently, or perhaps even physically meaningless, has its roots in the work of Guggenheim in the late 1920s. However, chemists have never been able to give up the idea of single ion activities, and by