Antarctic law has effectively managed geopolitical tensions related to territorial acquisition in Antarctica, largely due to the stabilising influence of Article IV of the Antarctic Treaty. This provision has successfully suspended contentious disputes over territorial claims, fostering cooperation within the Antarctic community. However, sovereignty-related tensions resurfaced when Antarctic states faced the obligation to submit data to the Commission on the Limits of the Continental Shelf to establish continental shelves beyond 200 nautical miles from baselines in Antarctic territories. This chapter examines how Argentina and Australia, both of which assert sovereignty over Antarctic territories, have addressed the geopolitical challenges stemming from the interplay between Antarctic law and the law of the sea in the context of their submissions to the Commission on the Limits of the Continental Shelf.