Narrator J. talks about his younger days of first learning the crafts of rafting, rowing, punting, and sailing in Chapter XV. Whether he really learned these skills, or whether he just dabbled in the endeavors from time to time with at least non-tragic results, is left to the reader’s judgment.
He describes times of “rafting in various suburban brickyards” and ponds, with the adventure becoming even more exciting when he is yelled at or pursued on shore by “the proprietor of the materials of which the raft is constructed.” In other words, he stole lumber or other stray pieces in order to make the raft in the first place. Most of his remembering is about how to deal with the person coming after him for the theft.
His encounter with sailing was with a friend, perhaps named Hector, when they rented a sailboat and went up the River Yare on a windy day. Naturally, they didn’t know what they were doing. First, J. got wrapped up in the sail as he tried to hang it. They initially hung it upside down; then, they hung it sideways. The boat eventually caught the wind and took off at a high rate of speed, and ended up getting stuck in a mud bank. The boys had to be rescued hours later by an old fisherman who towed them back to the boat's owner.
Neither escapade paints a picture of J. being comfortable, familiar, or adept at operating any kind of watercraft.
Even i dunno