Increasing endurance is a major challenge for battery-powered aerial vehicles. A method is presented which makes use of an updraft around obstacles to decrease the power consumption of a fixed-wing, unmanned aerial vehicle. Simulatory results have shown the conditions that the flight controller can fly in. The effect of a change in wind velocity, wind direction and updraft has been analysed. The simulations showed that an increase in either updraft or absolute wind direction decrease the throttle consumption. A change in wind velocity results in a shift of the flight controller’s boundaries. The simulations achieved sustained flight at 0 per cent throttle. The practical, autonomous tests reduced the average throttle down to 4.5 per cent in front of the boat. The unfavourable wind conditions and inaccuracies explain this minor throttle requirement during the final experiment.