I'm so excited to showcase a new aquatic algae for me - Tristan Taber of LSM suggests it might be a Palmodictyon algae. It looks quite spectacular up close - I used the 2x zoom on my cell phone, and draped the algae over an inverted ramekin in water before raising it up to highlight its filamentous form.
The algae felt a little slimy and gel-like to the touch, and not at all like the feel of wet cotton candy that metaphyton has.
It's free floating, and looks pretty nondescript lying in my frisbee before I stretched it out.