The Department of Justice says Jonathan Toebbe and his wife, Diana Toebbe, allegedly sought to sell sensitive military secrets about submarines to a foreign entity.
No cause has been established for the sinking earlier this month of the KRI Nanggala with 53 people aboard, but officials have suggested that it may have been due to an undersea wave.
The Pentagon says it will send airborne assets to help with the search as Indonesian officials say only a few hours of oxygen are left for the submarine's crew of 53 even if the vessel is intact.
Rescuers are scouring the Bali Sea for a submarine that disappeared this week. Officials say if the crew is still alive, they're expected to run out of oxygen by Saturday.
Submarine hobbyists are helping scientists in Montana do environmental research on the state's lakes. Researchers couldn't otherwise afford to rent subs, and it gives the hobbyists a sense of purpose.
A once-secret underground naval base in Crimea designed to preserve Soviet submarines in case of a nuclear attack is now a museum with an anti-American message.
Twelve previous government-funded expeditions had tried and failed to locate HMAS AE-1 and its crew of 35, which disappeared less than three months into the war.
"More than double the number of days have passed where it would have been possible to rescue the crew," a navy spokesman said. "We will continue the search ... there will not be people saved."
