This review article summarizes some recent insights into the strategies used by marine organisms to select surfaces for colonization. While larger organisms rely on their sensory machinery to select surfaces, smaller microorganisms developed less complex but still effective ways to probe interfaces. Two examples, zoospores of algae and barnacle larvae, are discussed and both appear to have build-in test mechanisms to distinguish surfaces with different physicochemical properties. Some systematic studies on the influence of surface cues on exploration, settlement and adhesion are summarized. The intriguing notion that surface colonization resembles a parallelized surface sensing event is discussed towards its complementarity with conventional surface analytical tools. The strategy to populate only selected surfaces seems advantageous as waves, currents and storms constantly challenge adherent soft and hard fouling organism.