A number of company's offer Bora Bora lagoon tours, and I've road-tested a few, but Lagoon Service was hands-down my favorite – the service is professional, the guide plays great ukulele and swimming and the food was excellent.
Although the idea of swimming with sharks may sound somewhat ominous, it is now one of the most popular excursions in the South Pacific. Originated on Bora Bora, the close encounter begins after you don a snorkeling mask and float in the shallow lagoon waters behind a secure rope. Docile sharks arrive in schools and are hand-fed by your guide just a few feet away. Later in the same tour, you'll stand in shallow waters as graceful rays circle the group with ballet-like movements. And there is also a stop for snorkeling through a coral garden in the aquamarine lagoon.
The trip concludes with a traditional picnic lunch that includes everything from poisson cru to all sorts of fresh fruits.
The sun is brutal here, and it is best to not only wear sunscreen, but cover up while swimming with a rashguard or T-shirt.