People watching is a wonderful occupation in La Rochelle, but there comes a time when it's good to get away from other people for a while ...
Not very well known (but easily walkable from the Old Port - or take the Bus de Mer / Water Taxi) is the coastal pathway that stretches from the Minimes marina, along the coast to the beach near Aytre and beyond.
Either walk or catch the Bus de Mer to Minimes and head for the beach. With the sea in front of you turn left and just keep walking (or take a bike) !
Great views of the sea approaches to La Rochelle, the replica of the "Phare du Bout du Monde" in the distance and then parcs to your left and more great sea views to the right. Up to about 8kms of fresh air - and not many people !