L5 Geographers were somewhat bemused on arrival at Ash Brook river, Carding Mill Valley to be handed bags of dog biscuits! It all become clear (and great fun!) when the method for collecting data on stream velocity was explained and pupils were then able to float their biscuits and time how long it took for them to move five metres downstream. Alternative methods were considered such as the use of a ping pong ball (not good for the environment if lost) and the use of a flow meter (ineffective in shallower water) before concluding that the dog biscuit method was indeed best. We tested a range of hypotheses over the course of the day as we made our way through the valley from the source of the river further downstream, ensuring that our Geographers are adept in the fieldwork skills necessary for the GCSE course.