P-8 Black Sea.

This is coolbert:

I  had to read this several time before I properly understood.

Russian submarine as having left port and sailed from the Baltic to the Black Sea.

"What Was a US Spy Plane Searching for Along Russia's Borders on V-Day?"

"On Friday, Russia's Defense Ministry confirmed the Pentagon's report that Russia scrambled an Su-30 fighter on May 9 over the Black Sea to intercept a US Navy P-8A Poseidon, which was 'conducting routine operations in international airspace.'"

"The expert [Sudakov] noted that recent reports suggested that one of the submarines might now be on its ocean passage from the Baltic Sea where it has undergone its final testing. Hence the US aircraft might have been waiting for it to obtain its acoustic profile, which is individual for each particular submarine and which will help to locate it in the future."

TRACKING A RUSSIAN SUBMARINE DURING VOYAGE FROM THE BALTIC TO THE BLACK SEA! HARDLY "SPY" OR ESPIONAGE AS THOSE WORLD ORDINARILY, GENERALLY AND COMMONLY UNDERSTOOD!

American submarine probably closely shadowing the Russian all the way up to the Sea of Marmara and the Bosphorus. Poseidon in international airspace and perhaps even pursuant to NATO mission following from that point forward. ROUTINE!

coolbert.