Merged seawater sound‐speed equations

Recent checks of published seawater sound‐speed measurements indicate that the Del Grosso–Mader data provide the best relationships with temperature and salinity, while the Wilson data have the preferred pressure dependence. Possible error sources in the original measurements are discussed. Anderson’s pressure‐dependence, based on the Wilson data, is applied to Del Grosso’s equation and to the Del Grosso‐Mader data, resulting in three new equations. The third and simplest equation seems preferable for most applications. The new equations agree well with Anderson in comparison with acoustically determined convergence‐zone ranges at sea.