In most cases and that is of course depending on weather conditions, a typical tour will take you outside the Reef, the water there will be around 10m/30' deep blue and you will be swimming with the curious Black Tip Sharks on the look out for a sardine. In the same area, you might also get to see some Lemon Sharks which are bigger in size (2m/6') circling on the bottom.
Next you will be navigating back inside the Lagoon and stop to see and have an amazing experience with the Sting Rays! They are very friendly and today are used to the humans and will come right up to you. The last stop before Lunch or a refreshment (depends on the tour) you will probably stop at the Coral Of Coral which is a very popular snorkeling spot in Bora Bora with many tropical fish to be seen.
Once done with the tour which will have taken you all around the Island, you might get to enjoy a nice lunch on a private Motu!
See video below