Even on a tight schedule, Seine River Cruise earns the hours.
Allow 1 hr (sightseeing).
Yes it's touristy, but floating past Notre-Dame, the Louvre and a sparkling Eiffel from the river is a genuinely good first-day orientation — especially at dusk. The operator-level call matters more than people think: Bateaux-Mouches runs the biggest boats with an open upper deck (the best seat) but only recorded commentary on a longer loop; Vedettes du Pont-Neuf are smaller and more intimate with a live narrator on the same core circuit. Either way, take the open top deck and skip the overpriced dinner cruises — a plain evening sightseeing boat does the job for a fraction of the price.