Sea level and current measurements from Trondheimsleia have been analysed and the parameters of the tidal ellipses for the major tidal components M2, S2, N SUB>2, and K1 have been calculated. Harmonic constants for sea level and tidal ellipse parameters have been compared with the corresponding data from a high resolution tidal model in order to validate the performance of the model. Short periodic oscillations with period about 40 minutes are observed at the time of peak tidal current at one station located in a channel with relatively strong tidal currents