Modern ship drives are characterized by high efficiency and durability. Due to the low costs of transporting goods, ships are one of the most important means of transport with a growing presence. As a result of the increased activity, the background noise levels have risen by about 25 dB in parts of the northern hemisphere, which can have a negative impact on the marine animals. The demand for quiet and compact marine drives has brought a new class of hubless propellers into the focus. The flow field of theses potentially quieter propulsion devices will differ from that of hub propellers due to the changed topology of the rotor blades and the lack of a shaft. This will also effect the emission of hydro acoustic noise. This paper will present numerical and experimental results on the hydrodynamics and the hydro acoustics of a small scale hubless propeller. The analysis of the transient hydrodynamic pressure and velocity fields from a SBES CFD simulation were investigated using the Proper Orthogonal Decomposition (POD). The results of the POD analysis were used for the identification of coherent flow structures in relationship to the hydro acoustic noise emission.