The movement of lionfish has been compared to a flamenco dancer snapping out a fan. For this photo, shot on a shallow reef in the Maldives, the photographer rotated his housing and fired his strobes on the rear-curtain sync to freeze the fish. The intent: give the feel of an image where everything is in motion.

Damien Mauric

Using a slow shutter speed to create movement produces a very different effect from an image where the subject is frozen with a fast shutter speed. In this case, the technique lends a wow factor to a Maldivian sunset over the Indian Ocean.

Imran Ahmad

This Flabellina pellucida against a star-trail background is a composite of 77 photos. Like this shot, most star-trail photos are taken as a series of more-moderate exposures (about 30 seconds), then blended together using star-trail software.

Alex Mustard

For fast-moving subjects — such as these blackfin barracuda on Sanganeb Reef, Sudan — get in as close as possible. The technique conveys how a fish school moves nearly as one and captures its massive, swirling beauty.

Gabriele Donati

Sharks are among the most elegant, powerful swimmers in the ocean. This image captures a silky shark — photographed off Camaguey, Cuba — and how it uses its tail like a propeller, swinging it back and forth to move forward.

Christian Vizl

A slow shutter speed can enhance the movement of a subject, providing another dimension to the image. In this case, the graceful swimming motion of the anthia — photographed in the Red Sea — makes it seem as if it is painted on canvas.

Mark Fuller

Twice a day, strong tidal currents push through Norway’s narrow sound, Skodjestraumen, a beautiful area for kelp. Add a creative effect by using a long exposure, and you can capture the movement of the swaying kelp in the ripping current.

Lill Haugen

The allusion of movement in this reef scene emphasizes the changing currents on a wall in Indonesia’s Misool region. The currents here can run in all directions; in fact, this particular sea fan has grown into a strange shape so that it can filter the water from whichever direction the current is coming.

Alex Mustard

A helmet gurnard flares its winglike pectoral fins as a warning and flees across the sand in Indonesia’s Lembeh Strait. A long exposure — in this case, 1/13 of a second — combined with panning with the subject, creates the sense of movement.

Alex Mustard