One of the aims of the ‘Optimizing propulsion’ project is to support rowers and coaches with real-time feedback in order to optimize performance. Last week, the VU, in collaboration with Surfnet and the Okeanos test-team tested whether the feedback that was provided to the rowers in the boat while rowing, could also be directly saved in the cloud, using 4G technology. This data can be used for off-line analyses, but the coach can also view it in real-time. In this way, coaches will be provided with objective information about important training variables such as boatspeed, individual rower power, acceleration, or stroke rate during the work-out ,on a stroke-by-stroke basis. The coach can immediately see the effect of his instructions to the rowers, which increases the efficiency of the on-water training sessions.