Copyright © 2018 by the International Society of Offshore and Polar Engineers (ISOPE) PIV measurements were carried out in a recirculating water channel at the Reynolds number of 43,000 to understand the three-dimensional flow structures around the free end of the cylinders with low aspect ratio piercing the free surface. Flow fields at different vertical and horizontal planes were presented for two aspect ratios, namely 2.0 and 0.5. The results showed the core of the longitudinal recirculation region (bubbles) varied at different planes for aspect ratio 2.0 and did not vary for aspect ratio 0.5. The difference of vortices showing up between aspect ratio 2.0 and aspect ratio 0.5 was also presented.