Yes, we did it two weeks ago, and it was great.

It's limited to 6 people, and you are led by Denis (can't remember his last name), who is a marine biologist. He first takes the group out for a deep water snorkel which is not pretty particularly, while he collects small coral specimens that are damaged in some way, and he talks about the different types of coral and how to tell if they are damaged or not.

Then you boat over to the Bora Bora Pearl Beach hotel, where he shows you their coral hospital and gardens. What they are doing is building small coral "reefs" (he calls them "toblerones" for the shape of the enclosures) under the OWB walkways of the hotel. Lots of fish, really interesting stuff about coral and how to save it. The collected damaged coral gets added to the collection. Denis is like Michael Poole (the dolhin guy)--passionate about what he's doing, and he makes you think hard about the importance of coral, how it is abused, and why it's so important.

The fish are really beautiful, and just "right there" by your feet--the water is only chest-high or less, so you just stroll around with your reef shoes. It was one of my favourite excursions.