In this paper, we present behaviors and interaction modes for a small underwater robot. In particular, we address some challenging issues arising from the underwater environment: visual processing, interactive communication with an underwater crew, and finally orientation and motion of the vehicle through a hovering mode. The visual processing consist of target tracking using various technique (color blob, color histogram and mean shift). The underwater communication is achieved through printed cards with virtual markers (ARTag). Finally, the hovering "gait" developed for this vehicle relies on the planned motion of six flippers to generate the appropriate forces.