Dr. Orest Ihor Diachok

It is with great sadness that we announce the passing of Dr. Orest Ihor Diachok, PhD, on July 22^nd 2026 in Fairfax, Virginia. Orest was born in Berlin on September 17^th 1940 to Ukrainian émigrés Theodosius Diachok and Stephania Wozniak. The family resided in a displaced persons camp before emigrating to the United States. Orest spent most of his life in the Washington, D.C. area and was a notable figure in the Ukrainian-American community. Among other volunteer roles, he was Head of the Shevchenko Scientific Society in the Washington, D.C. area. Orest received his Bachelor’s in Physics from the University of Maryland and his Doctorate in Physics from Georgetown University. Orest led an extraordinary life and his career was by all accounts illustrious. He was a prominent Marine Biophysicist who dedicated over fifty years of his life to the U.S. Navy. Orest conducted numerous overseas research experiments, published highly cited scientific papers, and held several patents. He was the Chief Scientist at the NATO Undersea Research Centre in La Spezia, Italy and Branch Head at the Naval Research Laboratory. Orest also worked at the Naval Oceanographic Office and the Johns Hopkins Applied Physics Laboratory, and aboard submarines, including the recommissioned USS Archerfish. Orest was full of incredible joy and positivity. He loved his family and his work for the U.S. Navy. He leaves behind his loving wife Olha, sons Mateo and Mark, brother Darian, sister Larissa, and a large extended family. He was predeceased by his son Andrew. A memorial service will be held on Sunday August 30^th at St. Andrew’s Ukrainian Orthodox Cathedral located at 15100 New Hampshire Avenue in Silver Spring, Maryland. A liturgy will begin at 10AM, followed by an 11:30AM memorial service, and a repast in the banquet hall at 12PM.