We developed a high-resolution ocean model to study marine debris dispersion across the Indian Ocean, from coastal scales to the open sea. Results show that model resolution and wave forcing, through both the Stokes-Coriolis force and Stokes drift, play a key role in shaping ocean circulation, seasonal energy budgets, and floating debris trajectories. High-resolution currents and wave forcing, especially during monsoons, increase the anisotropic spread and travel distances of drifting material.