Salvatnet is a lake in Namsos Municipality in Trøndelag county, Norway. With its deepest depth of 482 m, it is Norway's and Europe's second-deepest lake, after Hornindalsvatnet. Alternate sources give the depth as either 464 m (old manual method) or 482 m (modern echo sounding method) at the deepest point. The lake sits very close to the ocean, about 9 m above sea level at the surface and reaches to a depth of 473 m below sea level. It is a very large lake with an area of 44.96 km2, a volume of 6.97 km3, and a shoreline that is 105.61 km around. Salvatnet is a meromictic lake, meaning that the water is permanently stratified, often without oxygen in the lower depths (bottom water) due to density gradient and a lack of turnover. A meromictic lake often preserves records of the geologic past. The lower layer of the lake is highly saline and as a result denser than the higher levels of water. Other meromictic lakes in Norway; with old seawater in the lower depths include Botnvatnet, Kilevann, Rossfjordvatnet, Rørholtfjorden an arm of the lake Tokke, Rørhopvatnet, Tronstadvann, and Øvervatnet.