A thought I received in trance.

[Plenum]

water is commonly seen as a metaphor for the emotions.  Volatile, and that which is shaped by circumstances.

"Your own nature is water in that you as mind/body/spirit complexes are easily impressed and moved. Indeed, this is the very fiber and nature of your journey and vigil in this density: to not only be moved but to instruct yourself as to the preferred manner of your movement in mind, body, and spirit."

in regards to thoughts, I would more associate them with the element of air.  This stems from astrology, where the air signs (Gemini, Libra, and Aquarius) are arch paragons of thought and mental activity - this ties into their natural communicative abilities as well.