Each year we whittle down the thousands of submissions received in our annual contest to about 300 semifinalists presented to our judges. Selecting just three winning images in each of four categories is not an easy task, however, and the judges engage in a fair amount of spirited debate. You’ll understand why when you view our picks for the photos deemed worthy of an Honorable Mention.

See the full list of the 2018 Scuba Diving Photo Contest winners here.

PT Hirschfield

Mornington Peninsula, Australia

Behind the Shot: Calamari squid at Rye Pier on Australia’s Mornington Peninsula typically hover in small groups, keeping a cautious distance from ­divers. But this fearless animal befriended me, allowing me to photograph it for half an hour. To my delight, it swam from beneath the pier, positioning itself perfectly above me against a bright sun ball. I dialed down my aperture and shutter so as not to overexpose the image. Then I dialed down my strobe to gently light the animal, to capture detail while avoiding a silhouette.

Luc Rooman

De Melle-Turnhout, Belgium

Behind the Shot: This shot is double exposed in the camera. First, I took the sunrise, then I searched for the perfect subject underwater, and put the two pictures together in the camera. This picture was taken in early spring, when toads and frogs mate; the water is cold — 46°F — and shallow in this freshwater lake in Belgium near Turnhout.

Claudio Ceresi

Bali, Indonesia

Behind the Shot: I took this photo in Bali, at a Tulamben dive site called Melasti, about 72 feet down, during a night dive. The porcelain crab over a blue ­tunicate had eggs just about to hatch. After this shot, all the little ones exploded toward my lens — I had a thousand eyes watching me, all the babies that were near the lights of my torch.

Karmen Jones-Cox

Vava’u, Tonga

Behind the Shot: This was a very special ­humpback calf. While mom rested, the curious calf would rise for a breath and engage with me and four other swimmers; it was especially animated with its pectoral fins, reminding me of how humans use our arms and hands. In this shot, the whale’s reach is within a few feet of my dome port; I am shooting from the hip in “awesome experience” priority mode.

Christian Vizl

Yucatan Peninsula, Mexico

Behind the Shot: Cenote Aktun Ha is part of a great ring of ­thousands of cenotes found in the Yucatan Peninsula that form when limestone bedrock collapses to expose subterranean groundwater. They have been a fountain of inspiration since I started diving them in 1994, finding endless beauty in each one. The challenge for this image was to balance artificial and natural light — the intensity and angle of the strobe illumination had to be just right. I wanted to bring out the texture of the leaves without overexposing the skittish silvery fish.

Tianhong Wang

Lembeh, Indonesia

Behind the Shot: When I took the shot, this lovely crab, decorated with white “flowers” on seaweed, made me imagine a beautiful bride in a wedding dress. I decide to shoot head-on to clearly show its facial features and expression, and enhance the visual effects. I created a black backdrop through lighting methods, to get a clean background to highlight the subject and at the same time emphasize the orange and green colors, striving for harmony in contrast.

Lorenzo Mittiga

Bonaire, Caribbean Netherlands

Behind the Shot: In April, when this image was taken, there are no waves in Bonaire. So I came up with the idea of “surfing” ­underwater, knowing I would rotate the image. It took more than 100 tries — the surfer had to dive in and float up to the board, which was upside down, then hold that stance to allow me to get the shot. That morning was exhausting, ­considering that I was ­freediving and the surfer had to keep his eyes open all the time, but those three hours paid off with a great image.

Enrico Somogyi

Bali, Indonesia

Behind the Shot: This photo was taken in the wreck of the famous USAT Liberty in Bali. As I dived through the cargo room, I was attracted to the colorful, coral-studded passageways. My next dive on the wreck, I brought a circular fisheye lens. My girlfriend was willing to model, and a cooperative fish came over at just the right time. After a few shots, I had the picture I wanted.

Minh Tran

Anilao, Philippines

Provided Caption: Yellow pygmy goby in a bottle at Anilao

Shane Myers

Guadalupe, Mexico

Provided Caption: Submerged in Guadalupe's pristine waters, the shear power and awe inspired by the resident great whites is something zen-like that changes ones soul.

Jim Squires

Provided Caption: As a turtle once swam over me a night dive, I had this vision of it being backlit by a full moon. This day-night composite captures my vision, harkening back to childhood days "as the turtle swam under the moon.”

Joerg Blessing

Raja Ampat, Indonesia

Provided Caption: School of bigeye jacks on Raja Ampat's Blue Magic dive site.

Lucie Drlikova

Provided Caption: "FLORA - the flower fairy"

Stephanie Tuma

Provided Caption: Lion's mane jellyfish surrounded by little fish ascending to the surface

Kathrin Landgraf-Kluge

Lembeh Strait, Indonesia

Provided Caption: Red devil scorpionfish in Lembeh strait in October 2017. This photo was taken with a Canon G16 in a Fantasea FG16 housing using an YS-DS2 strobe with snoot and a 5+ macrolens.

Nicholas Samaras

Provided Caption: Underwater photo shoot with Greek Paralympian Antonis Tsapatakis

Becky Kagan Schott

Truk Lagoon

Provided Caption: A CCR diver checks out the small tank on the port side of the Nippo Maru in Truk Lagoon. I used different lighting techniques to make the tank stand out.

Raffaele Livornese

Provided Caption: A male pregnant pygmy seahorse (Hippocampus bargibanti), ready to give the birth to his babies.

Rune Rasmussen

Provided Caption: This picture is of my friend Andre swimming, in the aqua theater pool of the Allure of the Seas, where we do shows almost every night. This time the pool is used just by me playing around with my new camera and housing for the first time shot with Lumix gh5.

Enrico Somogyi

Lembeh Strait, Indonesia

Provided Caption: Hairy frogfish from Lembeh. Taken with a Panasonic LX100 Compact Camera. Double Exposure in Camera.