A Mark IV tank, part of the parade at the Lord Mayor's Show in London. (Photo by Topical Press Agency/Getty Images). November 1917

A lighting bolt flashes in the sky as U.S. Army M1A1 Abram tanks roll through the desert December 9, 2002 near the Iraqi border in Kuwait. (Photo by Joe Raedle/Getty Images)

Todd Bretl specializes in underwater photography, and is able to capture striking photos of aquatic life big and small. His photos of sharks are particularly striking; though he rarely faces hostility from the animals, he tries not to spend too much time looking through his viewfinder and many shots are framed by educated guesses and impeccable timing. What follows are photographs taken over the past several years on trips to the Bahamas and Isla Guadalupe, an island off the coast of the Baja California peninsula in Mexico. (Photo by Todd Bretl)

“This is the terrifying moment a diver came head to head with a shark as it swims inches away snatching a bite for dinner. The close encounter, captured off Bimini Island in the Bahamas, shows the hammerhead approaching diver Eli Martinez who bravely stands his ground as the giant beast approaches. Eli, free diving outside of a protective cage, carefully handled the sea creature despite its menacing razor-sharp teeth – but admitted they are extremely shy and need a lot of work to allow divers close to them. After multiple trips and hours of diving nearby they finally got used to Eli in January this year – hammerheads regularly visit these waters during the winter season”. – Caters News. Photo: Eli Martinez with hammerhead shark. (Photo by J. P. Zegarra/Caters News)

A destroyed T-72 tank, which presumably came from Russia, is seen on a battlefield near separatist-controlled Starobesheve, eastern Ukraine, October 2, 2014. The burnt-out remains of dozens of tanks and armoured vehicles in fields near the small village of Horbatenko bear witness to the ferocity of a battle that turned the tide of the conflict in eastern Ukraine. Among the debris, Reuters found the blackened carcasses of what military experts have since identified as two Russian army tanks, supporting statements by Kiev and the West that the rebels were backed by troops and equipment sent by Moscow. (Photo by Maria Tsvetkova/Reuters)

Two dummy tanks being pushed along a road by German soldiers. (Photo by Hulton Archive/Getty Images). Circa 1925

In this May 24, 2017, photo, DriveTanks.com customers drive on a tank course at Ox Ranch in Uvalde, Texas. The ranch is a free-roaming range filled with exotic animals, some to hunt, and home to DriveTanks.com, where tourists pay to transport themselves into another era and another life. (Photo by Michael Ciaglo/Houston Chronicle via AP Photo)