Essential characteristics of a turbulent boundary layer, bearing silt flocks in suspension, are described and interpreted with the help of a simple steady state model calibrated for the test region of the Math Modelsea project off the Northern Belgian Coast under near critical conditions : no net flux of particles through the bottom boundary. The model emphasizes the existence between the viscous sublayer and the classical Prandtl–Ka´rma´n logarithmic layer, of an ’’elastic sublayer’’ where gravity acting on the suspended load provides the necessary restoring force.