The isolated silicon vacancy in its neutral charge state has unambiguously been confirmed in electron irradiated 4H and 6H SiC. This was achieved by the observation of the ligand hyperfine lines arising from interaction with C-13 atoms in the nearest-neighbor (NN) shell and With Si-29 atoms in the next-nearest-neighbor (NNN) shell in optically detected magnetic resonance (ODMR) experiments. The complete hyperfine tensors for all inequivalent lattice sites have been deduced and are compared to the known hyperfine parameters for the negatively charged silicon vacancy in the two polytypes.