In former papers, it was reported that a measuring system was developed for the quantitative comparison of the skills of veteran scullers in working a "Ro-scull" with those of inexperienced scullers. In the previous report, with focusing attention on the scull lock as a fulcrum, the three-component force acting on the scull lock was measured and compared. The inexperienced scullers averagely showed a large longitudinal and vertical component force. In contrast, the veteran scullers were applying a large horizontal component force. Based on the above experimental results, the testee scullers' motions in working a Ro-scull were visually recorded in this report for the purpose to evaluate the skill of working a Ro-scull in the light of how testee scullers move their bodies. The below stated findings were obtained from the picture image analysis of motions of five testee scullers including three veterans. (1) The amount of motion of each part of testee sculler's body could be quantitatively indicated as a time series waveform from a motion picture taken by a digital camera. (2) The trajectory of Ro-scull head is similar to a circular arc centering on the point of origin while pushing Ro-scull outward. (3) According to the comparison among testee scullers, one veteran sculler showed the smallest amount of movement of right elbow and Ro-scull head. It is believed that the analysis of veteran scullers' motions in working a Ro-scull presents the key points to teach the trick of their way of working a Ro-scull when training beginners to work a Ro-scull.
