Jerry’s nosebleed causes him to make a wise decision that he immediately goes back on. The nosebleed is severe enough to give him a nasty fright, and he registers the sight of his own blood flowing over the rock and into the sea. The nosebleed makes him extremely dizzy, which leads him to become logically concerned about what happens if he gets dizzy while he is down in the underwater tunnel. He realizes that there is a possibility of him becoming trapped and dying there. He decides to go back to the house and try to get through the gap again next summer when he and his mother return to the beach for their annual vacation.

His logical thinking doesn’t last long. As soon as his nose stops bleeding—without even waiting for the accompanying headache to subside—he decides that this is his moment to try and conquer the underwater tunnel. In other words, while the severity of his nosebleed had caused him to stop and think, it ultimately did not stop him from going ahead.

As is often the case with boys his age, Jerry makes a poor decision. He is not really able to hold his breath for long enough to swim through the tunnel, and while his attempt is successful, he becomes aware along the way that he has risked his life. Fortunately, once he reaches the other side and conquers the tunnel, Jerry has no desire to repeat the adventure.