The rippling underwater plants are known as Eel Grass or American Wildcelery (Vallisneria americana).
Eel Grass is a rooted, submersed plant with ribbon-like leaves. It is common in spring runs where it provide excellent habitat for aquatic organisms including damselflies, snails and fish. Sometimes confused with Strap-leaf Sag, Eel Grass leaves are broader and blunter without the raised veins.
Source: Florida's Springs