I was cut on my big toe in Newport in the water and its shapped like a horseshoe what could of done it?

I was in the water a few summers ago in Newport's first beach. I was just in the water nothing but sand was around and I went up over a wave when I landed I felt a pain I got to land and I had a cut like a horseshoe on the side of my left big toe. Does anyone have any ideas what could of done this?