The moiré fringe wave visualization technique produces instantaneous records of the wave field, from which the propagation characteristics of the surface may be deduced. This is particularly useful for surfaces whose properties are time variant. Although the wave damping properties of the polymer monolayers examined were considerably more complicated than those of monolayers of simpler surface active agents, existing theory was shown to be adequate in explaining the observed effects on the basis of the surface tension and surface dilational elasticity of the monolayer. This agreement of theoretical prediction with observation supports the evidence for the existence of longitudinal surface waves. Using the moiré technique to investigate the time variation of solution‐adsorbed monolayers of poly (ethylene oxide) on water, it was found that this polymer produces from solution the same type of stable monolayer as is produced by spreading the material in a monolayer on a pure water substrate.