We propose to perform zero-field muon spin rotation studies of S=1 honeycomb antiferromagnet BaNi2V2O8 which is an ideal physical realization of the quasi-2D magnetic system. BaNi2V2O8 is a promising candidate to display a thermal decay of the Berezinsky - Kosterlitz - Thouless phase within the temperature range just above the ordering temperature TN, where BaNi2V2O8 behaves as a 2D XXZ magnet. Our goal is to measure and analyse the asymmetry relaxation function to extract the temperature Tcross where BaNi2V2O8 displays a crossover from 2D XXZ to 2D Heisenberg magnetic behaviour. Then, the dynamics of the decoupled spin-vortex/antivortex pairs in BaNi2V2O8 will be explored from the analysis of the line shape of the fast Fourier transform of the asymmetry relaxation function within the TN-Tcross temperature region.