A headshield sea slug pauses on a blade of grass in the U.S. Virgin Islands in the winning image of the University of Miami's 2012 amateur Underwater Photography Contest, whose results were announced this month.
(See more sea slug pictures from National Geographic magazine.)
"Everybody looked at that photo and said, Wow ... Everything is just so appealing to the eye," according to judge Michael Schmale, an amateur underwater photographer and professor of marine biology and fisheries at the university.
The judges—Schmale and two other underwater photographers—were also impressed by how sharply photographer Ximena Olds captured the tiny creature, which is less than an inch (2.5 centimeters) long.
"One of the great things about a contest like this is that it gets people seeing the ocean through other eyes," Schmale said.
"A really good photographer, like a painter or sculptor, doesn't just make a snapshot of something—but they capture something about the environment that strikes them."
Best Underwater Pictures: Winners of 2012 Amateur Contest
From the ocean's biggest fish to tiny sea slugs with big color, the stars of an annual contest help reveal "the ocean through other eyes."