Riverboat Port in Paris

I am assuming your port is in the 15th but don't know -- but assuming so the Île aux Cygnes is an island in the Seine that has the quarter size Statue of Liberty at its downriver tip and runs up to Bir Hakeim, a gorgeous bridge at its upriver tip. It is a lovely walk and the bump out on the highway across Bir Hakeim is a popular place for photo ops with the Eiffel Tower in the background. And of course cafes to take a break. Here is a walk we took many years ago one October that included this island and the Bir Hakeim bridge viewpoint. https://janettravels.wordpress.com/2011/11/01/stroll-on-a-sunny-oct-31-parc-citroen-to-the-eiffel-tower/

If your riverboat dock is not in this area -- well let us know where it is and maybe someone has a better suggestion.

You are arriving the day of the cruise departure ?

Kim's post is worth regarding -- it is pretty risky to time arrival for the day of cruise departure especially in this time of airline chaos. I'd at least have a plan b idea for getting to the next cruise stop just in case.

hey hey joy
my feelings are the same as Kim, are you flying from the united states or within a country nearby? this is a close call for disaster if the unexpected happened. on the other side, you may not have any issues
i would have Plan B set up if something happens the morning/day of flight to paris and know where the port is to pick up cruise.
does cruise offer a shuttle or take a taxi cab to port
any plans how you will get there, make a map with directions to have handy with you. i have seen the ugly when people have missed their cruise, saw them next day or day two pulling up luggage as we were getting off for shore excursions. good luck
aloha

Depending on the cruise line they will allow you to board at 10am but you only have access to public areas, not your room. You can even have lunch on UniWorld on day of arrival.

Same for Viking. What line are you traveling with? What port are you embarking from?