The results of ice and hydrological studies of the shallow Bay of Braganzavågen (Van Mayen Fjord Bay, West Spitsbergen Island) in March 2016 and 2018, supplemented with model calculations using a thermodynamic model, are presented. The model uses both known methods of localizing the phase transition region – the classical (frontal) for fast ice and in an extended area (two-phase zone) for bottom sediments. For real atmospheric conditions of winter 2015–2016, the new qualitative features of the process of ice formation in the adjacent layers of sea water and bottom soil are revealed. However, due to insufficient knowledge of the heat and mass transfer properties of bottom sediments, the question of quantitative estimates of the process remains open and can be clarified in special field experiments.