BEIJING, July 14 (Xinhuanet) -- An unmanned yellow submarine of the U.S. Navy is nearing the halfway mark in its effort to travel from New Jersey to Spain to collect scientific data along the way, media reported Monday.

It, less than 8 feet (2.4 meters) long and about 130 pounds (59 kg) in weight, will cover more than 3,800 miles (6115 km), the longest trip for the device.

"The big advantage is, it's totally unmanned," explained Conrad Lautenbacher, head of the National Oceanic and Atmospheric Administration.

"It can be done totally remotely," added Lautenbacher. "It can be controlled from a rec room in Ohio if necessary."

Like a glider airplane, the submarine uses wings to fly through the water as it dives and rises, seeking currents that will carry it where the researchers want it to go, according to Scott Glenn, a marine sciences professor at Rutgers. At the surface, it sends data to a satellite.

  On this trip, the glider is focusing on the temperature and salinity of the ocean, Glenn said.

Scientific information from the glider is shared with the Navy and other agencies and is expected to help answer some major questions in the next few years, he added.

(Agencies)