I'm always up for a marine reserve. A lot more waters need protection. Most people don't realize that if the seas are screwed up the rest will go with it. A lot of oxygen comes from the ocean plants, marine life is the core of the planet and it's not just a piece of blue water. With my eco speech out of the way, I only went to the underwaters of Italy and not in France. The cliffs or Bonifacio are great but I assume the marine life is similar seeing that they are in close proximity. I took a day trip to Maddalena which I don't think should be included as half the island is a town. Immediately I moved on to Caprera via a small road plus bridge. The entire island is a national park - great! I stopped at the first long beach and snorkeled around. It's pretty but I cannot speak for unique. I then drove to the east side to hike to Cala Coticcio. It's only 1.2km but it will take a good 25min with the boulders and steep “steps” between the oddly marked parking lot on the map and the tiny beach. It is a nice and popular hike and if a bit warmer would have more people at the beach. I find the ghoulish rock formations the best part of the island but I am sure this isn't the part they want to inscribe.

There is also a sign that all hikers need to have a guide. I am very sure nobody hikes with a guide or want a guide to hang around with you while you relax at the beach. Just maybe worth mentioning if in peak season they take this more serious. There is one section that is not kids or elderly friendly.