This report is concerned with further development and validation of the XFEM fracture mechanics analysis capability in VAST. In the present work, some of the limitations in the previous version of the XFEM fracture element were removed. The improved XFEM capability permits curved shell geometry with arbitrary orientations and cracks that pass through element corners. Pre- and post-processing capabilities for the XFEM element were developed in the TRIDENT system where the conventional and XFEM fracture elements are treated under a unified framework. In order to demonstrate the suitability of the XFEM element for spectral fatigue crack propagation analyses, a case study was performed using a practical problem involving crack growth in a frigate under certain operation conditions. The fatigue analysis was performed using the unit panel method where the stress intensity factors must be provided for each of the unit panel and rigid-body acceleration load cases. The crack increments predicted by the stress intensity factors from XFEM and conventional fracture elements are in good agreement and they both agree well with the measured data.