John Marsh sets out to find a short cut. He starts his slog in just his underwear and hat because he has a long paddle on the river ahead of him, so he wants to keep his jeans mostly clean. He cleans up enough to get in his boat, again; still in his underwear. The next we see of him, he's dressed in a long sleeve shirt and tight, low-waist jeans. The shirt comes off pretty quick, but he finished the trip in his jeans, which get completely covered in black mud.