Dentify a theme in "through the tunnel" and explain how the setting of the story contributes to that theme

In "Through the Tunnel," the negative connotations and dangerous imagery associated with the "wild bay" help to convey the theme that growing up can be a painful and scary process.  Jerry longs to grow up and to fit in with the "older boys -- men to Jerry" who swim and dive at the wild bay rather than remain on the "safe beach" with his mother, a beach later described as "a place for children."  The way to the wild bay is marked with "rough, sharp rock" and the water shows "stains of purple and darker blue."  The rocks sound as if they could do a great deal of damage to the body, and the stains are described like a bruise.  It sounds painful.  Then, "rocks lay like discoloured monsters under the surface" of the water and "irregular cold currents from the deep shocked [Jerry's] limbs."  This place sounds frightening and alarming and unpredictable.  Given that this is the location associated with maturity, with the time after childhood, we can understand that the process of growing up and becoming a man is a time that is fraught with dangers and fear, because Jerry endures both in the "wild bay."