The U.S. Navy on Saturday said it plans to deploy a maritime aircraft to help Argentina in its search for a submarine that went missing on Wednesday with 44 people on board. The news came as Argentina's military said bad weather was hampering search operations. With “nearly 50 percent” of the search area already covered, Argentine navy spokesman Enrique Balbi told reporters bad weather in the area “really complicates the work” as search crews scramble to find the vessel. The ARA San Juan, a German-built vessel first launched in 1983, was last seen Wednesday in the San Jorge Gulf off the coast of southern Argentina's Patagonia region. “We have not been able to find, or have visual or radar communication with the submarine,” Balbi said. “The submarine knows that if it does not have communication with land for this long, it has to surface,” he said. Among those on board the missing navy submarine is Eliana Krawczyk, Argentina's first female submarine officer, authorities said.