In the paper the results of vector-algebraic and harmonic analysis of current measurements are described. Using of short-data methods of tidal analysis we calculated the tidal constituents of tidal currents for Srednyaya Salma and Uzkaya Salma straits (Keret Bay, White Sea). Maximal velocities of tidal currents in those straits are equal 21-22 cm/s for principal lunar semidiurnal harmonic and 11-12 cm/s for principal solar semidiurnal tidal wave. Mean velocities of semidiurnal tidal currents (23-24 cm/s) and mean velocities of spring semidiurnal tidal currents (32-34 cm/s) are estimated via harmonic constituents of tidal currents. Measurements show that tidal currents have reversing type, and significant impact of nonlinear shallow-water tidal harmonics. Semidiurnal tidal currents turn synchronously in the both straits. The phase differences between tidal sea level fluctuations and tidal currents correspond to standing semidiurnal tidal wave. This work is a preliminary but necessary step towards study of tidal regime of the Keret estuary. Now we can set correct open boundary condition in the numerical hydrodynamic model of the Keret Bay by using tidal sea level and current fluctuation (radiation open boundary condition). Importance of radiation open boundary condition is confirmed by simulated tidal velocities of existing models of Keret Bay, which are understated in 2-3 times in contrast instrumental measurements. Refs 20. Figs 3. Tables 2.