Holland type submarine of the Plunger class undergoing trials at Electric Boat Company

Holland type submarine of the Plunger class undergoing trials at the Electric Boat Company, New Suffolk, Long Island, New York. Submarine running along at periscope depth. Periscope of the submarine. Several times the boat disappears below surface and rises again (porpoising). It makes way on the surface. Civilian testing crewmen in business attire climb out of conning tower and walk on the deck. They start back down into the conning tower. Men on the deck as the submarine runs along the surface. Submarine tied up at the pier, men walking around on deck and using a plank to walk to the pier..