The verses describing the splitting of the Yam Suf (Reed Sea) say a strong wind blew overnight before the sea split. To me, this implies a gradual process of moving a great deal of water.
On the other hand, we have midrashim which imply it was a suddenly occuring phenomenon, saving Nachshon from drowning. Also, the verses say Moshe stretched out his staff and the sea split in response.
If it was a miraculous, quick transition from sea to dry land, what was the strong wind for? Or am I interpreting it wrong?