Tonight, the Seventh Night of Passover, marks the actual time when the Israelites crossed the Red Sea.
There is a vast world under the sea (after all, two thirds of the world is covered by water), but it is largely concealed from our eyes.
Jewish mysticism explains that the sea represents the deep spirituality within G-d's order of creation that is present, yet hidden from our view.
In our lives, splitting the sea means training our minds eye to see beyond the surface of the physical to perceive the spiritual G-dly dimension that lies within everything. When we succeed in doing so, we are in effect splitting the sea once again, but this time in a personal and internally impactful way.