Shapes of a water- jet in different regimes are analyzed on the basis of fluid theory. High speed photography is used to record the turbulence of the water-air interface. The water-jet contours are detected and reconstructed by using digital image processing algorithms. The ray tracing method is employed to investigate the optical losses produced by the surface perturbation. The results show that the amplitude and frequency of turbulence have a great impact on light propagation under the effect of total internal reflection. At the stage of incipient turbulence, no optical losses is caused since the wave amplitude and frequency are the relatively small. But when the amplitude and frequency of turbulence exceed certain threshold values, the power losses tend to increase so that it weakens the ability to guide light of water-jet in this kind of situation.