"Once More to the Lake" is structured as a chronological narrative; it is developed with passages of exposition as White compares and contrasts the lake he visits with his young son with the lake he remembers from his own youth. White observes many similarities; much of what he sees and experiences seems not to have changed since he had been there as a boy. Fishing, going to the farmhouse for dinner, and an afternoon thunderstorm all seem the same as he remembers. The sense that nothing has changed comforts him.
However, throughout the essay the comforting comparisons are juxtaposed with disconcerting contrasts. The dirt path leading to the farmhouse is different; the tracks of the horses' hooves that White remembers from his youth are gone now; only tire tracks from motorized vehicles are visible. He also notices a disconcerting difference in one specific element of the lake's environment:
The only thing that was wrong now, really, was the sound of the place, an unfamiliar nervous sound of the outboard motors. This was the note that jarred, the one thing that would sometimes break the illusion and set the years moving. In those other summertimes, all motors were inboard; and when they were at a little distance, the noise they made was a sedative, an ingredient of summer sleep . . . But now the campers all had outboards. In the daytime, in the hot mornings, these motors made a petulant, irritable sound; at night, in the still evening when the afterglow lit the water, they whined about one's ears like mosquitoes.
It is these expository passages of contrast that finalize the theme of the narrative: despite the illusion of sameness, of timelessness, White sometimes feels during his visit to the lake with his son, things have changed because time has not stood still.