The next day after leaving Papeete, Earth I arrived in Rangiroa, Earth which is one of the largest atolls in the world (here is a link on what an Atoll is).  So basically this is a giant lagoon in the middle of the ocean and has many reef formations within it and as such there is lots to see under the water.  so i joined a snorkelling excursion as the air  mattress just would not cut it out here.

Rangiroa, Earths location link