 There are two spots high above water along the left and right walls  of Origin Beach where there were once glyphs (Or some creature) that  was removed from the game. However if you use your sonar against  those walls you still get messages from them. The left one says: "We  hear song in the ocean!" "We hear our kind in the sea!" "Never have  we heard songs in the sea!" The right one says: "You sing our song  under the waves 