By 2030, a new amphibious transport ship is to be available for the Dutch Royal Navy. In light of the foreseen rise in airborne operations from the ship, more insight is desired into the impact of ship design choices on helicopter operational availability. There is need for a predictive tool, which can be used in the early design phase of the ship. This thesis presents a novel method for the prediction of ship helicopter operational limits (SHOLs) of conceptual ship designs. The tool predicts a SHOL diagram on basis of local mean flow velocities in the ship domain, obtained with a RANS CFD method. The tool consists in the basis of simplified relations, which are calibrated by means of a correlation to existing limits established during sea-trials. A validation of the predictive tool shows the ability to predict up to 85% of the SHOLs of an existing Dutch navy ship.