We started on Palm Beach. On the map  it is the closest point you see to the Island. 

We kayaked out to the right of the green island and made it to the split between the big green and the tiny rock island at the right.

The big island is  Sainte-Marguerite. There is a monastery on the Cannes side. I saw a few WW2 bunkers and this is the island where The man With The Iron Mask was held. 

http://en.wikipedia.org/wiki/Man_in_the_Iron_Mask

http://en.wikipedia.org/wiki/Île_Sainte-Marguerite