The study considers simultaneous plasma velocity measurements in the eastward direction carried out by the Clyde River SuperDARN HF radar and Resolute Bay incoherent scatter radar RISR-C. The HF velocities are found to be in reasonable agreement with RISR velocities up to magnitudes of 700–800 m/s while for faster flows, the HF velocity magnitudes are noticeably smaller. The plasma flows eastward component inferred from SuperDARN convection maps (constructed for the area of joint measurements) shows the effect of smaller HF velocities even at smaller velocities. We show that the differences between the instruments can be significant and prolonged for observations of strongly-sheared plasma flows.