If one had to select one fixed sampling location for physicochemical parameters in a large lake such as lake Malawi, how could he/she go about it?

In the 1940s a British scientist by name of Beauchamp located a fixed sampling station for physicochemical parameters 5 km north-east of Nkhata Bay in the northern offshore waters of Lake Malawi. The lake is about 400 metres deep at that Beauchamp's sampling station, but no details were given on why that location was considered representative of the whole lake.   I'm intending to do my sampling at that same location. However, as several years have lapsed after Beauchamp did his work and temporal changes may have occurred since then, and no clear reasons were given why that one location was considered representative I tend to hesitate. Could anyone help with a suggestion?