Tern in question

I was out doing turtle patrol when I saw a Tern that was definitely looking different than the rest of the bunch. I noticed that it was bigger than a Least and smaller than a Sandwich. Of interest was the fact that the bill was black, slender and a bit decurved. The part (lore) before the cap was white with black striation. The dark black cap extended down to the nape. Also, I noticed the legs were very delicate looking and had a red/maroon-ish color. I was using my cell phone and zooming in to get the photo while staying a bit away so as not to scare it off. The actual color of the bird was paler than it appears in the photo. Also, please note the shadow of the tail in the sand which seems to extend past the wings making me think that it might be a Roseate.