Herbert Van Cott Wetmore was the oldest of three children born to Daniel Clarence Wetmore, a shipwright originally from Nova Scotia and Charlotte R. Slocum of New London, Connecticut. He had a younger brother, Ralph Wetmore (1881-1967) and sister, Leah Anna (Wetmore) Converse (1887-1923). During the 1920's, his uncle, Walter M. Slocum was the Postmaster in New London. Herbert enlisted in the US Navy in 1897 and was assigned to the battleship, USS Iowa where he was a shipwright during the Spanish American war and assigned until 1903. Thereafter he served on the dreadnaught USS Colorado and in the Philippines. He was promoted to Carpenter (warrant officer) in 1909, the same year he married his Finnish-born wife, Amalia Tilus in Manhattan (11/20/09). He was only the second Carpenter on the new dreadnought battleship, USS Texas (BB-35) where he was assigned from 1915 until February 1918. During WWI he was temporarily promoted to the rank of lieutenant and after the war, his rank reverted to Chief Carpenter. He and Amalia had two children, a boy who died in infancy in 1914 and a daughter, Helen, born in 1917 at the Brooklyn (New York) Naval Hospital. Following WWI, Herbert and Amalia maintained their residence at Middletown, RI, where he built his home at 146 Fair View Ave. In the 1920's, he was assigned to the repair vessel, USS Vestal that worked to raise the sunken submarine S-4 in 1926, and following that he was assigned to the destroyer tender USS Dobbin.

Chief Carpenter Wetmore died suddenly due to a cardiac condition in May 1933 at the age of 57 while stationed at the Naval Training Station, Newport, RI. He had served 36 years of continuous service in the Navy and was posthumously advanced in rank to Lieutenant, in the Construction Corps. He was survived by his wife, teenage daughter, and brother, Ralph Wetmore of New London, Connecticut.