Although not a recurring feature in maritime delimitation case law, the availability of provisional measures has the potential to modify State conduct and influence the temporary arrangements that States pursue pending the resolution of a maritime boundary dispute. The need for temporary arrangements is also recognised in Articles 74 and 83 of the UN Convention on the Law of the Sea (LOSC), which require in paragraph 3 that States ‘in a spirit of understanding and cooperation, shall make every effort to enter into provisional arrangements of a practical nature and, during this transitional period, not to jeopardize or hamper the reaching of the final agreement’. These arrangements are not to prejudice the final delimitation. This chapter considers provisional arrangements under the LOSC and its case law, highlighting the judicial interpretation of the relevant LOSC provisions in Guyana v. Suriname. This analysis considers how provisional arrangements have impacted on final maritime boundaries delimited by courts and tribunals. The chapter further focuses on provisional measures, examining the criteria for ordering such measures in maritime boundary cases. The inter-relationship between provisional arrangements and provisional measures is drawn out in terms of possible overlap of standards and how the two might be expected to work in harmony.