Arsenne aborts his motion to pick up one of the oars, and backs up to the middle of the boat.
Once the ship's boat is under way and Mr. Arvodair has a steady rhythm going...
... Arsenne takes out his 'Fine Journal', ink and pen to do a quick sketch of the Island from this vantage point. He draws an outline of the island with emphasis on the relative dimensions and distances of various rises and landmarks. When someone looks over his shoulder to see what he is doing he causally explains:* "I just need three more minutes to catch the important details. This sketch may become become the basis of an important painting some day!"
Spoiler[I am taking it for granted that the boat is small enough and that there is manifestly enough time for all this. Otherwise, he keeps his journal safe as he can inside the backpack]