<p>Surface velocity is crucial in fighting oil on water. Technical guidelines give detailed instructions for the respective positioning of oil booms in flowing water bodies. In practice, the local velocity in rivers and streams is usually unknown and oil fighting will be done by fire brigades which are neither trained nor equipped to measure it. For an assessment of potential surface velocities at defined oil boom anchorages in the city of Hagen, Germany, runtime measurements of surface floaters (oranges) were correlated with gauge data and image based velocity measurements. The findings shed light on the suitability of the different cross-sections for oil control as well as on the applicability of simple yet reliable measuring methods.</p>