[1] Coumantaros began his career in Buenos Aires, Argentina, where he worked for a grain trading company.
[1] Coumantaros gave his last yacht, Boomerang to the US Merchant Marine Academy, in Kings Point, New York, for use in training.
[1] Coumantaros was inducted into the National Sailing Hall of Fame in 2018 with a Lifetime Achievement Award.
[4] Coumantaros and his wife, Sophie Yannagas, had one son, John, and three daughters, Flora, Maria Christina and Eugenie.
[2] He was a Grand Archon of the Greek Orthodox Church, and served on the board of the Archdiocesan Cathedral of the Holy Trinity on the Upper East Side of New York City.