The Maritime Research Institute Netherlands (MARIN) has recently started a Joint Industry Project (JIP) on developing two new propeller series for Controllable Pitch Propellers (CPPs). Following the well known Wageningen B-series and Ka-series, the new C-series comprise open CPPs whereas the new D-series concern ducted CPP's. The primary objective of developing the new CPP series is to help the shipbuilding and offshore industries in understanding the off-design per-formance of the CPPs, for which systematic information was lacking.