The Great Ouse River is located in the North Sea of the United Kingdom, it measures 230km and is one the longest rivers in the United Kingdom, its name “ouse” is from the Celtic or pre-Celtic origin and probably means “water”.
Wikipedia contributors, “River Great Ouse,” Wikipedia, The Free Encyclopedia, https://en.wikipedia.org/w/index.php?title=River_Great_Ouse&oldid=897338026 (accessed May 23, 2019).

Nilfanion, River Great Ouse map, CC BY-SA 3.0