Why does Guan Yin ride a dragon? Someone had once asked here "Why is Kwan Yin riding a sea turtle?", but what I'm more curious about is why is she seen on a dragon? There are many images or the Bodhisattva riding a dragon, one I posted being but one example. But who/what is the dragon? Is there a story behind it? I've heard the dragon is a symbol of wisdom and purity, others have suggested the dragon represents a wrathful force subdued by Guan Yin underfoot, but really what's the case here? Is it merely symbolic or is the dragon a literal entity (sentient or otherwise)? Any information would be appreciated (not modern "New Age").
Wikipedia says that she is "protector of fishermen, sailors, and generally people who are out at sea".

A Chinese dragon is esteemed (a symbol of the emperor), and "traditionally symbolize potent and auspicious powers, particularly control over water, rainfall, typhoons, and floods", also prosperity and good luck and so on, rulers of weather and water.

So I assume that riding a dragon like that symbolizes control over the sea (part of being "protector of fishermen and sailors").