Uw tips:The Metro is quick and easy to get around the city. I would definitely suggest that you bring some swim wear and take a short boat journey and explore one of the nearby islands off the coast.
The Port of Marseille has an energy of excitement surrounding it. The marina has many great restaurants and bars along with a number of street performers. A nice place to stay in the evening and enjoy the evening breeze whilst sipping on some lovely wine! There are many ferries leaving Port Marseille that will take you for day trips to the nearby islands.