PROPELLA is a non-linear unsteady panel method used for analyzing various propeller-related problems. Propellers with 2 to 10 blades, as well as nozzles, rudders, stators, and/or propellers pods, can be assessed. Operating conditions can range from bollard through to vanishing thrust. By using uniform flow analysis, the optimum design efficiency can be determined and parameters such as pitch, rake, skew, number of blades, and section shape can be examined. Non-uniform flow can be assessed in which a realistic inflow (axial, tangential, and radial values) is specified to allow calculation of operational characteristics in a ship’s wake. Cavitation characteristics and resulting thrust loss can be determined for heavily loaded propellers. The PROPELLA code also has the ability to model blockages, such as the close proximity of submerged ice pieces, and to assess the hydrodynamic effects of operating in such extreme conditions. This allows the effects of cavitation to be assessed as propeller blades move in and out of regions of blocked flow. Output includes shaft thrust and torque, in- and out-of-plane bending moments, spindle torque, and instantaneous pressure distributions. This data can be used as input for propeller structural design calculations.