What you see in front of the mouth of the guy in the boat looks like the Aztec glyph for talking.
But as far as I know, the Mayans didn't use such a glyph.
To me it is nothing but someone exhaling smoke, or maybe it is someone shouting (to the one busy drowning): "Hold on, I am on my way !!".
Edited by Abramelin, 26 October 2012 - 09:49 AM.