Dive 1604 with ROPOS focused on installing over 15,000 feet of cable across the summit of Axial Volcano. With this much cable, the drum weighed over 6,000 lbs, making it too heavy to be latched into the underbelly of ROPOS. Instead the cable drum was lowered over the starboard side of the ship using one of the ship’s wires and winches. ROPOS was also launched and about 600 feet below the ship it imaged the drum with its forward-looking sonar. Carefully, the ROPOS pilot and navigator drove the vehicle toward the drum until they were close enough to image the drum directly with the ROV's high-definition camera. ROPOS and the drum then descended to the seafloor, 5,000 feet below the ocean's surface. The cable drum was gently placed on the seafloor with the winch as ROPOS ensured there was a safe landing zone. ROPOS then attached cable to the junction box, and began laying cable on the seafloor.