Visualisations of liquid flow in a layer with a deformed free surface were conducted and a special attention was paid to systems with surfactants where the Marangoni effects may appear. Three types of visualisations were done using tracer techniques: a) transport of solid particles at the liquid surface, b) direct visualisation of a velocity profile inside the liquid layer, c) recording of flow instability in the layer. Reported observations directly confirmed that the presence of surfactant is responsible for flow intensification in the liquid layer due to the Marangoni effect. The possibility of hydrodynamic instability formation during fast deformation of the interface was detected.