Left-side three-drops water radical, the side-form of 水. It anchors 潮 as a water phenomenon, the tide, the daily rise and fall of the sea. Same family: 海 (sea), 河 (river), 流 (flow), 浪 (wave). 潮 belongs to the rhythmic, large-scale water words.
Right side 朝 supplies the sound, exact cháo. It also adds a faint semantic flavour: 朝 depicts the sun rising through grass next to the moon, naming dawn. 朝 plus water gives 'the tide that arrives at sunrise.'
