I've surfed north side a bunch and the rays love to feed on fish kicked up in the shorebreak. One time I literally had a ray break the surface and flop right onto the nose of my board. Nearly needed to change by boardies.
They are VERY common around here, I have stepped on quite a few and felt their slimy back as they slither away, but luckily never got the barb stuck in my foot (knock on wood). SHUFFLE YOUR FEET PEOPLE!
How long ago was this? I met someone in DE probably around 2008-2009 who told me that happened to them.