Before the annexation of Crimea by Russia, Roman Mokriak served on a submarine Zaporizhzhia in Sevastopol. In 2014, he moved to Odesa because Mokriak’s family could not accept him continuing service in the occupied peninsula. At one point, his mother suggested he changed the profession, but he firmly decided to serve further. In Odesa, Mokriak served on the missile boat Pryluky, in 2016 he headed the boat Berdyansk. During the passage from the port of Odesa to the port of Mariupol, at the end of November 2018, his boat and two other ships were fired at by Russian troops.