A visitor holds an Israeli-made rifle during the 8th International Land and Naval Defense system exhibition, in New Delhi, India, on February 6, 2014. (Photo by Anindito Mukherjee/Reuters)

In this Friday, December 4, 2018 photo, a half sunken cruise ship lays on its side, in the Gulf of Elefsina, west of Athens. Dozens of abandoned cargo and passenger ships lie semi-submerged or completely sunken around the Gulf of Elefsina, near Greece’s major port of Piraeus. Now authorities are beginning to remove the dilapidated ships. Some of them have been there for decades, leaking hazards like oil into the environment and creating a danger to modern shipping. One expert calls the abandoned ships “an environmental bomb”. (Photo by Thanassis Stavrakis/AP Photo)

Extraordinary images of the cruise ship by Jonathan Danko Kielkowski from his book Concordia, published by White Press. The German photographer swam out to where the ship – which ran aground off Tuscany in 2012 with the loss of 32 lives – is moored. Francesco Schettino, the ship’s captain, was jailed for 16 years over the accident. (Photo by Jonathan Danko Kielkowski)

Participants of the “Torture Ships” walk to the pier where the Ship of lacquer and leather will undock with hundreds watching in Friedrichshafen, Germany on June 23, 2018. (Photo by Felix Kästle/DPA)

A General Atomics MQ-9 Reaper stands on the runway during “Black Dart”, a live-fly, live fire demonstration of 55 unmanned aerial vehicles, or drones, at Naval Base Ventura County Sea Range, Point Mugu, near Oxnard, California July 31, 2015. (Photo by Patrick T. Fallon/Reuters)

North Korean leader Kim Jong Un (front) stands on the conning tower of a submarine during his inspection of the Korean People's Army (KPA) Naval Unit 167 in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang June 16, 2014. (Photo by Reuters/KCNA)

Filipino Muslims ride on top of a vehicle as they celebrate the end of the holy month of Ramadan in Cotabato city, in southern Philippines, July 16, 2015. Picture taken July 16, 2015. (Photo by Marconi Navales/Reuters)

Members of the Royal Navy respond to a simulated fire in a Vanguard-class submarine control room training facility at Clyde naval base in Faslane, Scotland on January 21, 2016. (Photo by Photograph: Danny Lawson/PA Wire)