Birds diving in the surf

I was at the beach a couple of weeks ago. It was late in the day and I went to a spot that doesn't draw the crowds. It was me and maybe 2 others looking at the waves. I could see about 5 birds, smaller than sea gulls, flying over the water. Then "splash" a bird dove into the water. I supposed it was trying to catch a fish. The bird was very close to land. It kept doing this over and over.
No one else seemed to notice this activity. Had they seen these birds before? I hadn't and I come to the beach a lot! I looked the species up online and found that their behavior and coloring fit that of terns.
There is a tern colony on Faulkner's Island off the Guilford shore that would explain their presence, but why hadn't I seen them before? Maybe they usually stay closer to home and fish. What a neat experience. I never did see a bird come up victorious, with some food. It was neat to observe this little bit of bird behavior though; a little something different than the food fight over a few scattered french fried I observed later in the week between a group of gulls. One of the gulls was coveting a hamburger wrapper with some cheese stuck to it. It looked like he was planning on eating the entire piece of paper just to enjoy the cheese. People really need to remove their garbage when they leave the beach.