Final answer:
The character referred to in the question, who utilizes one oar to paddle and the other as a raft, is the oiler from Stephen Crane's story. The oiler's efforts, along with those of the captain, the cook, and the correspondent, contribute to their survival at sea.
Step-by-step explanation:
The character who uses one oar to paddle and the other as a raft in Stephen Crane's story is the oiler. Throughout the excerpts, it is clear that the oiler takes a leadership role in navigating and maintaining the dinghy in the open water, often exchanging roles with the correspondent. The captain, despite his injury, assists in directing the others and devising survival strategies, such as suggesting to use his overcoat as a sail. While the cook appears to be somewhat passive, often sleeping or keeping out of the fray. It is in the camaraderie and division of labor among these four characters—the oiler, the correspondent, the cook, and the captain—that they are able to survive as long as they do in their dire circumstances at sea.