Anyone happen to know what it looks like when sperm floats in dirty mudwater?

There's a huge puddle in my backyard, so I wondered what it would be like to fap into it. But I guess there's a clearing in the foliage along my fence that I wasn't aware of, so one of the neighbor's nephews (6y/o I think), whose family was over for 4th of July, watched for I don't know how long. I caught him looking before I got the chance to finish my experiment.