Abstract. In the context of the DFG research training Group Baltic Transcoast the scalar transport of discharged submarine groundwater and the included tracer substances will be investigated. The research focus is the mixing of ground water under the influence of waves in shallow coastal water. The waves will be generated by a Piston type wave generator and can be varied with respect to the specific wave parameters. In the water channel a permeable sea bed model is installed which allows the intrusion of a florescent tracer fluid into the measurement area. The transport of this tracer in the water column is affected by the wave motion and will be analysed using optical measurement technology. The methods used are on the one hand the Particle Image Velocimetry, to determine the velocity field in the measurement area. On the other hand, simultaneous Laser Induced Florescence will be used to obtain the concentration field. Thus, the relation between the unsteady velocity field and the mixing of the tracer can be determined quantitatively.