I’m pretty sure everything in Neo Venezia is an actual thing.
But yeah, it seems to be the on-water equivalent of a fun run. Even saw an Australian boat every now and then. Curiously, they seem to go in the opposite direction in the video than they do in the chapter - in the video, they start at the Piazza San Marco, then head out across the lagoon to Murano and back, then travel down the Grand Canal from Cannaregio back to the Piazza. In the chapter, they also start and finish at the Piazza, but appear to row into town first.
In any case, not a bad chapter. I would have liked more scenes of Akari interacting with the townspeople, though. Two doesn’t feel like enough. The first panel of page 165 has always made me think of Monopoly money. I’m also amused that まめ is a colloquialism for “blister” and is a homophone for 豆, just as “corn” as a synonym for “blister” is a homophone for… well, “corn”.
Only issue with language: page 165, panel 3, あまあまのあんまみーやよ. I know what あまあま means, but Googling あんまみーや turns up so many different pages using the entire phrase あまあまのあんまみーや, but few actually reference Aria, making me wonder if it’s a standard phrase. Or at least it’s entered the common parlance, like “beam me up, Scotty”. None of the results seem to explain it, in any case.