The cruises compared here
Both boats sail the same central stretch of the Seine and both show up when you search for a river cruise in Paris. They are built for different jobs. One is a tour that brings you back to where you started. The other is a shuttle with nine stops.
The price difference is small, so the decision comes down to how you plan to spend the day.
1What each ticket is
The Seine river cruise is a one-hour round trip with Bateaux Parisiens. It leaves from Port de la Bourdonnais below the Eiffel Tower, turns at the Île Saint-Louis and returns to the same pontoon. There are no stops and you cannot get off on the way.
Batobus is a pass valid for 24 or 48 hours from first use. Boats circulate between nine stops: Eiffel Tower, Invalides, Musée d'Orsay, Saint-Germain-des-Prés, Notre-Dame, Jardin des Plantes, Hôtel de Ville, Louvre and Place de la Concorde. You can board and leave as often as you like while the pass is valid.
2Time on the water
A full Batobus loop takes about two hours, twice as long as the cruise, because the boat docks at every stop. Boats leave the Eiffel Tower stop every 30 to 45 minutes, so each time you get off you should allow for a wait before the next one.
The cruise is one uninterrupted hour at a time you choose in advance. If your day is tightly planned, that predictability is worth having.
3Commentary
This is the biggest difference in what you experience on board. The cruise gives each passenger an audio guide in English and 13 other languages, and the operator says a guide adds live commentary.
Batobus has no guide. Its listing describes an app that you open by scanning a QR code, with commentary delivered over the boat's Wi-Fi. That means your own phone, your own headphones and enough battery. Neither the listing nor the operator states how many languages it covers.
4When Batobus is the better buy
Batobus pays off when you string sights together along the river: say the Eiffel Tower in the morning, the Musée d'Orsay after lunch and Notre-Dame before dinner. Each leg replaces a metro ride with a boat ride, and the 24 hours can straddle two days if you start in the afternoon.
Both boats are tagged wheelchair accessible in the catalogue if you declare it when booking. Batobus describes its boats as heated and glass-covered with an open-air deck, so the comfort level is similar to the cruise boat.
5When Batobus lets you down
It stops early. The timetable in the listing ends between 5 pm and 8 pm depending on season and day of the week, so there is no night sailing. If seeing Paris lit up from the water is on your list, only the cruise does that.
Stops can also close. The listing warns that when the river rises after heavy rain some stops may not operate, and the Batobus website shows the live status of each one. Check it on the morning you plan to use the pass.