The tour boat ride that we recommend is accessible from Pont Neuf, a 7 minute walk from the Relais du Louvre.
Although this walk is beautiful all year, the best time to do it is at the end of the day during the summertime. We tested the ride for you in pleasant weather and had a great time.
The cruise lasts an hour and the commentary is in French and English. You will see Paris's main monuments and learn interesting things. But beyond the words, we hope that the images will speak to you. We filmed our ride. Here it is :
Turn left upon exiting the hotel and keep going until the Quai du Louvre. Then continue on to the Pont Neuf. The ride is very pretty. You can then extend it (see our recommended route).
Prices may vary. Check or buy your tickets online, valid for one year on the website (http://vedettesdupontneuf.com/billets/). The hotel's concierge will also be happy to do it for you. Otherwise, you can always buy tickets on site, there is usually no queue.
After the ride you can reach Vert-Galant square and then Dauphine place and finish with Sainte Chapelle. A true concentration of good things close to the hotel.
Enjoy your visit!