Adhesion mean that water droplets can cling to other surfaces such as walls, ceilings, even you. Just as interesting is the cohesive property of water where the molecules stick to themselves. This is how droplets form in the first place. There is a special type of cohesion called surface tension. Surface tension refers to how molecules bind at the surface of water forming a stretchy layer at the top.
Skimmers uses surface tension to travel.
Obviously, direct contact with the surface will penetrate the liquid, however, glancing or light steps of a water skimmer foot will not break the surface. So you see, it's quite simple. By taking advantage of the properties of water and developing a very soft footstep, the water skimmer is able to move in this most unusual manner.