Grace always has work that exceeds the humans’ perception. God didn’t say to Moses; sorry, I have no solution for your problem… I wonder why did you come to the sea?
There weren’t bridges or ferryboats at that time.
But God always works through faith; the true faith. Some of people,that followed Moses, complained, saying to him; did you bring us to this place in order to make us die! But not everybody have the sight of faith.