We took the Batobus (river taxi) from the Notre Dame location down to the Eiffel Tower. This is a great way to see the Seine from the river, though it is a river taxi (can be crowded). There are stops at all the major sites along the Seine: the Louvre, Notre Dame, Eiffel, Musee D'Orsay, etc. We saw some dinner cruise-type boats, and next time we may try that. We spent a couple of hours picking out great cheese, fruit, bread, chocolates, and wine and had a little picnic out on the lawn in front of the Eiffel Tower. It was a great evening!