Her name is:
Carmenta, Roman Goddess of Childbirth.
The English alphabet has 26 letters, 25 of which behave either as consonants or vowels, and one, Y, behaves as both - the chameleon. But how do we get from the alphabet to bosoms? The English alphabet is adapted from the Latin alphabet, and legend has it that Carmenta, the Goddess of childbirth, changed many letters of the Greek alphabet to give us the Latin alphabet.
Her name is:
Penelope, wife of Odysseus. He is Odysseus.
tmpearce pointed out in their answer that the Greek Isles are a great destination for reef snorkeling. But who is the Chameleon? The goddess Athena appears throughout the Odyssey in many different forms to assist Odysseus on his quest to be reunited with his wife's sweet bosoms.
Attempt #3, we're getting more far fetched here. Her name is:
In August, 1803, three ships named Porpoise, Cato, and Bridgewater set sail for India from Sydney, Australia. On their way past the Great Barrier Reef, the navigated through an area today known as Wreck Reefs (25 reefs clue). The Porpoise and the Cato ran aground on a shoal amidst the reefs (chameleon clue, shoals disappear and reappear), and beat against the reef until they sank. Sadly, I am not aware of any particular treasure known as the Bosom of India that would have made this solution a better fit. But what we do know is that India in the early 1800s was an enormous exporter of textiles, and bosom can refer to the portion of a lady's dress which contains her bosom, so these ships were sailing to find bosoms from India for their bosoms in Australia.