Willem (Bill) Christiaan Pieter Jansz, in the middle, and his shipmates. He was on the U.S.S. Aroostook. The USS Aroostook was the Eastern Steamship Company's Bunker Hill converted for planting the World War I North Sea Mine Barrage. Bunker Hill was built in 1907 at Philadelphia, Pennsylvania for passenger service between Boston and New York City. Bunker Hill and her sister ship Massachusetts were among the eight ships acquired by the U.S. Navy in November 1917. The two coastal passenger steamers were converted to minelayers at the Boston Navy Yard.
Here is a letter he wrote to his little sister Marie in 1931.