波

Three-drop water radical on the left - the side-form of 水. Marks 波 as a water phenomenon: ripples, swells, waves moving across a surface. Same family as 浪 wave, 涛 surge, 漪 ripple. The radical anchors the literal physical meaning, while the abstract sense (a wave of news, an emotional swell) extends from there.

Right side 皮 supplies the sound (pí → bō, regular b/p drift). 皮 itself depicts a hand stripping the hide from an animal - the surface layer being lifted. That 'surface' image meshes nicely with 波: a wave is the moving surface of water. Same phonetic appears in 破 to break, 婆 old woman, 坡 slope, 玻 glass.