Surface tension forms a strong bond at the surface of a water body.

Surface tension in water owes to the fact that water molecules attract one another, as each molecule forms a bond with the ones in its vicinity. At the surface, though, the outmost layer of molecules, has fewer molecules to cling to, therefore compensates by establishing stronger bonds with its neighbors, this leading to the formation of the surface tension. Take a look at the following figure, in which the molecules at the top are the ones found at the surface of the water, and you will understand the process better: