The demand to suppress vortex-induced vibration (VIV) in the offshore industry is increasing nowadays. VIV is one of the biggest impacts that caused fatigue damage to the marine risers and pipelines. In exploring the mechanisms of VIV reduction by vortex generators (VGs), the experimental measurements in a water flume were performed. The experiments compared the wake of a stationary bare cylinder with a VGs cylinder at a uniform flow with Reynolds number 8,400. The velocity measurement was sampled at a frequency of 200 Hz and was measured by an Acoustic Doppler Velocimeter (ADV) instrument. From the ADV data, it was found that the signal correlations of turbulent flow and the percentage of acceptable data after the filtering process using WinADV of VG cylinder flow was higher than those of bare cylinder, and quite similar with the no-cylinder wake.