At 13 feet long, seven feet wide, and some 3,000 pounds, fisherman Erik Eidi made the catch of a lifetime about fifteen miles off the Washington coast.

Despite its massive proportions and incredible weight, his unique prize didn't put up a fight. That's because the Bellingham, Wash., cod fisherman didn't reel in a fish, but what is believed to be a Russian communication device that dates back to the Cold War (search).

"I'm sure the Navy would love to check this thing out. If it's something they've never seen before maybe it could help us," said Eidi.

Eidi's hunch that his discovery had national security value was verified when the Navy wanted to conduct an investigation. However, under maritime law, the artifact belonged to Eidi and after negotiations he agreed to let the U.S. Navy (search) "borrow" the Russian artifact.

"Anytime something like this floats up we may want to look at it. That's exactly what some of our Navy officials are doing right now. It will be determined if this is of interest or not. This is very old," said Lt. Cmdr. John Daniels.

The Navy plans to return the device to Eidi as soon as they complete the investigation. The fisherman sees the investigation as an appraisal because he wants to cash in on his find. Eidi even said he's willing to negotiate directly with Moscow for the best price.

Click in the box near the top of the story to watch a report by FOX News' Dan Springer.