At the beginning of the novel, Tish visits Fonny in jail and they speak over a phone, separated by a glass barrier. During their conversation, Tish works herself up to say what she has come to tell Fonny: "Alonzo, we're going to have a baby." Fonny says nothing at first, and they just stare at each other. Baldwin describes this image using a simile:
I looked at him. I know I smiled. His face looked as though it were plunging into water. I couldn't touch him. I so wanted to touch him. I smiled again and my hands got wet on the phone and then for a moment I couldn't see him at all and I shook my head and my face was wet and I said, "I'm glad. I'm glad. Don't you worry. I'm glad."
The glass is not perfectly transparent and is warped in places, making Fonny's face difficult to see. The distorted glass makes his face look "as though it were plunging into water." This simile figuratively describes Fonny's face as it appears to Tish. Also, it more abstractly depicts Fonny's rush of emotions in his shock over finding out he will be a father, like water rushing over his face. The rest of the passage above extends the simile: just as Fonny's face, wrought with emotion, looks like "it were plunging into water," Tish's hands and face get wet with sweat or tears. It is as if the overwhelming emotions of the moment overflow onto both of them, leaving them damp.
There is a final turn on this simile later in the conversation when Tish, speaking ironically, decides they will keep the child: "Well, we ain't gonna drown it. So, I guess we'll have to raise it." Through a variety of images, the simile connects water to Fonny and Tish's relationship, their baby, and the emotions around it, while still connecting to the physical image of the warped glass border. This figuration is especially striking because Tish regularly compares the Tombs, where Fonny is imprisoned, to "the Sahara," a wide desert where scavengers like lawyers and bondsmen prey on the poor and underprivileged. As such, the couple's love and concern for their child, represented by water, forms a figurative contrast to Fonny's dire imprisonment.
After months of imprisonment, the courts repeatedly postpone Fonny's trial, despite the best efforts of Hayward, the White lawyer the family hired. Tish describes how Hayward continues his efforts despite Fonny's case seeming futile, using his "charm, patience, money, and backbone of tempered steel." But Hayward, try as he might, cannot speed up the courts, as Tish describes in a simile:
But the calendars were full—it would take about a thousand years to try all the people in the American prisons, but the Americans are optimistic and still hope for time—and sympathetic or merely intelligent judges are as rare as snowstorms in the tropics.
Tish points to a problem that continues to exist in America to this day: too many men are unjustly imprisoned for more than a small portion of them to ever walk free. At the center of this problem, to Tish, is the courts, because judges who might be fair to a Black man are "as rare as snowstorms in the tropics." This simile is somewhat hyperbolic, as surely there are some sympathetic judges in New York, but it never snows in the tropics. Still, Tish uses that hyperbole to make her point: the odds of finding a fair judge for Fonny are perilously thin.
Note the contrast between this meteorological simile and the common "Sahara Desert" motif in the novel, which Tish uses to describe the wide, inhospitable halls of the prison that holds Fonny. In both cases Tish images the injustices of the structures of power as atmospheric, geographic problems, outside of the control of people like her.