Hi,
I find this very decent local place (compared to the other glitziest restaurants in French Riviera) called Les Perles de Monte Carlo. It only serves local oysters, lobsters and seabass. it's right at the tip of Port de Fontveille.
Has anyone tried this? How is pricewise? and i think you could climb up to its upper deck and view the wonderful facade of the Oceanography Museum and surrounding yacht port