This study presents cavitation development and cavitation erosion predictions for the benchmark cases of NACA0015 hydrofoil and PPTC propeller (VP1304) by using Computational Fluid Dynamics (CFD). Three-dimensional, unsteady cavitating flows around the hydrofoil and propeller are simulated using Detached Eddy Simulation (DES) with SST (Menter) k-⍵ turbulence model . Two-phase flow is modelled using Eulerian Volume of Fluid (VOF) approach with cavitation formation predicted by Schnerr-Sauer cavitation model. Predicted cavity structures on the hydrofoil as well as cavitation development and performance analysis for the propeller agreed fairly well with the experimental data given in open literature. Erosion on the hydrofoil and propeller are predicted by Intensity Function Method (IFM), Gray Level Method (GLM) and a new proposed approach, Erosive Power Method (EPM). Particularly, the erosion predictions obtained by the EPM, showed remarkable correlation with the damaged area observed from paint tests on the NACA0015 hydrofoil. Qualitative erosion predictions on the PPTC propeller for zero shaft and inclined shaft conditions are presented for the first time in the literature, which seems to identify regions of potential cavitation damage. Consequently, it is believed that this study would lay an important foundation for the widespread application of the EPM in the future.