What does the shark incident in part 5 of "The Open Boat" reveal about the correspondent’s and captain’s perspectives?

In part 5 of “The Open Boat,” the correspondent is on rowing duty when he sees a trail like “blue flame”; when he spots the fin speeding through the water, he realizes that a shark is creating that trail. Looking toward the captain, whose face he cannot see, he thinks the man is asleep. The oiler and cook are definitely asleep. He wishes that someone were awake to provide sympathy. As the shark continues to lurk around the boat, the correspondent wishes for company. Swearing at the shark, he experiences its presence as just one more factor in their predicament instead of reacting with panic. Still, he would rather have had company and wishes that at least one of the others were awake.

After the shark grows bored and moves off, eventually the night ends, and the captain perks up and speaks to him. The correspondent asks if the captain had seen the shark.

"Yes, I saw him. He was a big fellow, all right."
"Wish I had known you were awake."

The facts that the captain did not speak when he saw it and that the correspondent did not wake him indicate the mutual respect they have for each other, as well as the captain’s apparent confidence that the shark did not pose an immediate threat. In addition, it seems that the captain trusted the correspondent’s skill as a rower, expecting that he would remain calm in that situation.

What does the shark incident in part 5 reveal about the correspondent's and captain's viewpoints?

In part 5, the correspondent is taking his turn rowing; he and the oiler, Billie, are the only two of the four men who can really row: the captain is injured and the cook is physically unable. All of the others seem to be asleep. This is when he sees the "dark fin" cut through the waters around him and the trail of phosphorescence evidently left by the shark as it circles the boat. It seems to be waiting, perhaps, for its opportunity to feed. However, the narrator tells us that "the presence of this biding thing did not affect the man with the same horror that it would if he had been a picnicker."

The correspondent, then, has become somewhat inured to danger as a result of the sinking of the ship and his time in the lifeboat. His emotions are less intense and volatile, even when faced with something that would typically frighten him. Instead of panicking, he continues to "dully" watch the sea and swears to himself under his breath so as not to wake the others. He would prefer to not be alone with the horrifying creature and wishes that someone would wake up to commiserate with him. No one does, and he will not wake them only to allow them to be scared when they were sleeping relatively comfortably.

The captain does not reveal that he was actually awake here until part 6, and the conversation he has with the correspondent suggests that he, too, has been altered and hardened by their experiences. He only remarks that the shark was "a big fellow," and nothing else. Both men seem to be much less emotionally affected by the danger the shark poses as they would normally be because they already face such extreme danger from the ocean and sun. They have grown used to danger.