1890 a treaty between UK and Germany was signed respecting the spheres of influence in the two countries in Africa. The dividing line was in the centre of ‘main channel’ of the River Chobe, however a disagreement exist regarding the boundaries of the Kasikili/Sedudu island, and the legal status of the Island.
1996, by special agreement the two states refer the question to the ICJ
(18) neither Botswana nor Namibia are parties to the VCLT, but both of them consider art 31 (interpretation) is applicable inasmuch as it reflects CIL
(34) Parties agree that the flow, volume of water carried, plays an important role in determining the main channel
(40) Court: main channel is the part of the Chobe that offers more favourable conditions for navigation