The movement of single air bubbles under a downward facing inclined solid surface has been investigated in motionless distilled water body. The effects of surface inclination 0 and bubble volume V on the terminal Froude number are studied in details. The bubble volume was varied in the 0.3-9 cm(3) range and the inclination angles up to 10 degrees in a gravity driven system. For a typical correlation curve of the terminal velocity UT versus the volume at a given inclination it was found that the increase Of UT with V is not monotonous and that four distinct sub-regimes, each characterized by a specific bubble shape, exist. The effect of inclination on UT is More sensitive at both low V and low 0. The different sub-regimes are explained qualitatively. In addition, the drag coefficients for moving bubble underneath a solid surface are presented. (c) 2006 Elsevier Ltd. All rights reserved.