The problem of active, or driven, panel motions of marine vehicles altering the turbulent boundary layer properties is discussed. The coherent (vorticular) structures in a turbulent boundary layer can be altered by the motions of a panel causing those structures to grow more rapidly and, as a result, become prematurely unstable and burst. In addition, the motions of the panel can produce vortices that interact with those that are naturally produced, and change the character of the boundary layer. The motions of the antinodes of the panel can also increase or decrease the surface shear stress, if the panel is, respectively, above or below its mean position. The cumulative effect of the active-panel motions, then, could be to increase the boundary layer drag. An outline of the analysis of this phenomenon is presented.