This technical note examines the feasibility of physically modelling unstable water flow in the form of fingers in the vadose zone. A scaling analysis is performed based on published expressions for the width and velocity of fingers, as well as the distance between fingers. Particular reference is given to the use of a geotechnical centrifuge as an experimental apparatus for modelling this phenomenon. Initial results are presented for 1g and 10g fingers from a preliminary experimental program undertaken to explore the analysis. These results agree with the scaling analysis presented and indicate that finger scaling using centrifugal modelling techniques is possible.