The Russian sub (which the submainers have been rescued from) got tangled in a underwater antennia. What are these used for and why is it placed underwater?
It is not clear at this time what ensnared the sub. Early reports suggested a discarded fishing net, but Russian officials have discounted this. It’s possible it was caught on some sort of submarine communications cable. The most recent story I’ve seen detailing the successful rescue of the sub indicates only that some unspecified cables had to be cut to free it.
I heard one report that it was a listening device, possibly dating back to the cold war, to monitor any foreign submarines.