What is the wisdom behind the presence of the wave that came between Noah and his son when he was drowning, and was it a mercy from God to Noah so that he would not see his son drowning?

Noah's son drowned because he refused to board the ark with his father, insisting on seeking refuge on the mountain, believing it would protect him from the water. However, Noah replied to him that there is no protector from Allah's decree except for those upon whom He has mercy. Then the waves came between them, and he was among the drowned. The Quran depicted this scene to show the intensity of the horror. The waves coming between Noah and his son was not out of pity for Noah from seeing his son drown, but rather to prevent either of them from reaching the other.