The H-class submarines had a length of 150feet overall, a beam of 15feet and a mean draft of 12feet. They displaced 358LT on the surface and 467LT submerged. The boats had a crew of 2 officers and 23 enlisted men. They had a diving depth of 200feet.[1]
For surface running, they were powered by two New London Ship & Engine Co. 4750NaN0 diesel engines, each driving one propeller shaft. When submerged each propeller was driven by a 170hp Electro Dynamic Co. electric motor. They could reach 14kn on the surface and underwater.[1] On the surface, the boats had a range of 2300nmi at and 100nmi at submerged.[2]
The boats were armed with four 18-inch (450 mm) torpedo tubes in the bow. They carried four reloads, for a total of eight torpedoes.[2]
H-8 was launched on 14 November 1918, three days after the signing of the Armistice with Germany, and commissioned on 18 November 1918. From there she sailed to San Pedro, California, where she was attached first to Submarine Divisions 6 and 7 (SubDivs 6 and 7). Operating with her sister ships, H-8 engaged in extensive battle and training exercises out of San Pedro, varying this routine with patrols off Santa Catalina Island. In company with SubDivs 6 and 7, and tender, H-8 departed San Pedro on 25 July 1922 and arrived in Norfolk, Virginia on 14 September. She decommissioned there on 17 November. Her name was struck from the Naval Vessel Register on 26 February 1931. She was sold for scrapping on 28 November 1933.