story are in a small boat in the open ocean; their larger ship sank, with most of the crew onboard. They have been at sea for nearly two days when the story starts, and the sea itself is rough and harsh—they risk capsizing and drowning all the time. Crane describes the waves and sea as follows:

These waves were frightfully rapid and tall; and each boiling, white top was a problem in the small boat.

The boat cannot compete with the height and danger present in the waves, and as a result, the men are in constant danger of death. The cook’s main job on the small boat is bailing out the water that is continually filling the bottom. The sea also presents other natural dangers to the crew, like starvation, dehydration, and predators like sharks.

The correspondent, one of the crewmen on the small boat, has a moment to reflect that nature isn't really against the men; instead, it is indifferent to their struggles and problems. The sea doesn’t care for them, and that is part of why their danger seems so terrible:

It represented to the correspondent the calm of Nature against the struggles of the individual—Nature in the wind, and Nature in the sight of men. Nature did not seem cruel to him then, nor kind, nor dangerous, nor wise. But she was not interested, completely not interested.

The idea that it is indifferent to the struggles of humankind makes nature seem even more sinister. A person or animal has a motive; it attacks or steals for a specific reason. Nature in its indifference hurts and helps indiscriminately, and that chance is disconcerting. The men have to contend with the existential dread of knowing that their fate is in the hands of random chance rather than in their control.

Based on the wording of your question, I'm not sure if you mean to inquire about character vs. self conflicts or character vs. character conflicts. In terms of character vs. self, I think we see such a conflict within the injured captain. On the lifeboat, he finds himself

buried in that profound dejection and indifference which comes, temporarily at least, to even the bravest and most enduring when, willy nilly, the firm fails, the army loses, the ship goes down. The mind of the master of a vessel is rooted deep in the timbers of her, though he command for a day or a decade [...].

The captain seems to struggle against this dejection and indifference, continuing to issue instructions to the oiler and others in order to maintain the proper direction; however, he also seems to give into these profoundly upsetting feelings from time to time as well.

In terms of character vs. character, we see such a conflict between the cook and the correspondent when it comes to life-saving stations and houses of refuge. The cook is certain that a certain house of refuge is nearby and that they will be spotted by the crew. However, the correspondent argues, saying, "'Houses of refuge don't have crews.'" The two bicker back and forth for a short while longer.

Despite these minor conflicts, the major conflict of the story is the one of character vs. Nature. It is nature against which the men struggle: the waves, the sharks, the sun, the saltwater (as opposed to fresh, potable water). It is nature that does not care whether the men live or die but just keeps doing the natural things that nature does.

"The Open Boat" is a short story by Stephen Crane based upon the shipwreck he was involved in en route to Cuba, an experience which left him stranded in a small lifeboat with three other men off the coast of Florida for thirty hours. The story parallels this event through the narration of the correspondent. The correspondent is a man who is shipwrecked alongside a captain, a cook, and an oiler and forced to survive by floating in open water in a small boat.

In terms of classical conflict structures, "The Open Boat" demonstrates the theme of man versus nature, as the story tosses the protagonist and his companions into an unstable situation in which they are forced to confront the uncontrollable forces of the sea. Part of this struggle involves coming to terms with the indifference that nature seems to have toward their suffering. In that sense, the story could also be viewed as thematically addressing the idea of "man versus boat" in that their small dinghy serves as the container for their struggle. It enables their survival and allows them to "get an idea of the resources of the sea in the line of waves that is not probable to the average experience." It thrusts upon the four men a new perspective, and in doing so, it forces the correspondent to wrestle with his isolation and uncertainty about his fate.

"The Open Boat" by Stephen Crane is a naturalistic story based upon Crane's own experience of being shipwrecked when he was a journalist. In this story, the view of nature is unromantic, and lacking in any sentiment. The emphasis, of course, is upon a struggle to survive, depicted with dark and unredemptive tones. Crane depicts the men on the boat as symbolic of human endurance against an indifferent universe.

Significantly,the story opens with the men totally engrossed in their private struggle:"None of them knew the colour of the sky." As they row, the correspondent pulls at one of the oars, watching the waves, and wondering how he has come to be there. In this small dinghy, the men are truly at the mercy of the sea that seems a force against them:

As each slaty wall of water approached, it shut all else from the view of the men in the boat, and it was not difficult to imagine that this particular wave was the final outburst of the ocean, the last effort of the grim water.  There was a terrible grace in the move of the waves, and they came in silence, save for the snarling of the crests.

At the mercy of mere Chance, the men watch as a man waves a coat, but it blends into the gloom.  The men in the boat "swear like men who were being branded" at their bad luck.  Through their minds runs this collective refrain repeatedly as they try to make sense of their predicament:

"If I am going to be drowned--if I am going to be drowned--if I am going to be drowned, why, in the name of the seven mad gods who rule the sea, was I allowed to come thus far and contemplate sand and trees?  Was I brought her merely to have my nose dragged away as I was about to nibble the sacred cheese of life?"

The men's internal railing against nature denotes the absurb sense of importance that man imagines for himself against mindless Chance.  This concept is symbolized by the appearance of the shark that swims around the boat as most of the men sleep and the correspondent feels that he alone realizes its danger. Indeed, it is an indifferent and mindless universe that allows the oiler, the best sailor of all, to drown as the others survive the experience. All of the men's struggles come down to their unified efforts and fortunate achievement--except for Billie--of reaching land without being attacked by the shark or overturned by the sea's waves.  Yet, in their final heroic acts, the men absurdly feel that they can "interpret" what has happened.

Crane’s narrative opens with the men on the boat bemoaning their fate. The cook repeatedly exclaims, “God! That was a bad one.” The oiler has to avoid the incoming water. The captain is described as “feeling defeat and despair.” All of the anguish is a result of nature. The boat’s occupants have been waylaid by the sea. Within the first handful of paragraphs, Crane shows that the men on the boat are fighting a not-very-winning battle with nature.

For another example that illustrates the men’s struggle with nature, consider what Crane compares the journey to. Using a simile, he says, “The boat was much like an animal.” Specifically, the boat is similar to a “jumpy horse.” By linking the boat to a restless horse, Crane reinforces the uneasiness of the men. It explains that their interaction with nature is not calm but chaotic. In other words, it’s a struggle.

One might want to parse the diction that Crane employs throughout the story. Sometimes, it can feel like Crane is narrating a war story—only instead of fighting an army, the men are battling a sea. This could be why Crane points out “the secure bond between men” at sea. It’s as if those on the boat are on some kind of combat mission that requires them to stick together.

The violent, warlike diction also applies to the waves. “A new sound struck the ears of the men,” Crane says about the new set of waves that are about to confront the men. He goes on to talk about the sea’s “roar.” He then documents how the waves “break and roll over the little boat in a mass of boiling white and gray.” The forceful diction suggests that the struggle can be seen in terms of warfare. Nature is continually attacking the men on the boat, and the men have to figure out how to survive its figurative artillery.