evidence: Administrative divisions 10 regions; Barima-Waini, Cuyuni-Mazaruni, Demerara-Mahaica, East Berbice-Corentyne, Essequibo Islands-West Demerara, Mahaica-Berbice, Pomeroon-Supenaam, Potaro-Siparuni, Upper Demerara-Berbice, Upper Takutu-Upper Essequibo [...] Waterways 330 km (2012) (the Berbice, Demerara, and Essequibo Rivers are navigable by oceangoing vessels for 150 km, 100 km, and 80 km respectively) [...] Guyana-Suriname: Suriname claims a triangle of land between the New and Kutari/Koetari Rivers in a historic dispute over the headwaters of the Courantyne River