The Coastal Ocean Marine Prediction Across Scales (COMPAS) system is an open-source, three-dimensional, unstructured mesh ocean modelling framework developed by CSIRO to enable high fidelity prediction of oceanographic processes in shelf seas and coastal zones. Here, we showcase recent improvements to the modelling framework, focusing on numerical accuracy and computational performance, variable resolution unstructured meshing capabilities, and the development of advanced numerical techniques designed to enhance the representation of eddy-rich turbulence and mixing dynamics. Examples of high-resolution modelling in Australian shelf and coastal waters are presented in detail, highlighting the unique capabilities of the model to resolve complex circulation across varying spatial scales.