West Basin Lake, a small saline maar near Colac, Victoria, has a salinity differential between mixolimnion and monimolimnion of 40‰. There are also marked differences in pH, oxygen, and hydrogen sulfide concentrations in the two zones. The mixolimnion stratified during summer and as it cooled in autumn the lake became mesothermal and finally by winter the temperature profile was inverted. Meromixis appears to be of recent ectogenic origin and its present low stability indicates imminent destruction.