The run of bright long days and short drives has meant we have had nearly full batteries. Yesterday, we were again drifting lazily down the river and mostly using less power to the propellor than we were soaking up from the sun. Once the boat race we encountered had finished though, the organisers wanted us to hurry through the course so that they could start the next one. There was some confusion, and we were then asked to go back a bit. It took quite a bit of power to go back up stream and then hold station against the current.