- Helicopters, battleships and minesweepers hunt for vessel
- Emergency radio call in Russian picked up by Swedish military, report says
- Russia denies any vessel in Swedish waters
- Expert: It's easy to a submarine to hide in coastal waters
Be it a Russian submarine or be it not, whatever has been lurking beneath the waves of the Stockholm archipelago since last week is not only drawing threats of martial force from Sweden's military, it's also getting on Lasse Schmidt's nerves.
He putters around the archipelago with tourists in a small decommissioned military sub originally designed as a target for naval battle exercises.
And now some of his countrymen are gunning for him.
They think his submersible is what the navy detected as a potential intruder into its sovereign waters on Thursday. The military has been trawling the Baltic waters ever since.
The news has his business' phone ringing, with more people booking tours. But most of the calls are annoying, he says.
"Many people believe we caused this military operation," Schmidt said, "and they call to demand that we pay the bill for it."
Schmidt has continued the tours despite the underwater drama, informing the navy closely about his moves, and cutting a wide berth around the battleships, minesweepers and helicopters looking for a suspicious something.
The government won't say what that something is, but Sweden's press is reporting the military is looking for a submarine, maybe a Russian one.
Swedish intelligence picked up a radio distress call last week -- in Russian -- which set off the defensive reconnaissance, major daily newspaper Svenska Dagbladet reported.
The transmissions were directed at the Russian enclave of Kaliningrad, 330 miles (530 kilometers) south of Stockholm, on the Baltic's southern shore, The Local reported.
The search has reignited Cold War intrigue reminiscent of the blockbuster movie "The Hunt for Red October."
A Swedish military spokeswoman warned Tuesday that they "are prepared to use anything necessary to bring the vessel to the surface if we need to."
The same day the military called underwater tour operator Schmidt.
"They...told us to cancel the trip because of security reasons," he said. "I assumed something had happened."
There were reports in the press that ships hovered for an extended period over one spot.
Moscow has said it has no vessel in Swedish waters and suggested Sweden ask the Netherlands if it is one of theirs stationed nearby. The Dutch said it wasn't, according to an Agence France-Presse report.
Confirmation may be hard to come by, former NATO commander James Stavridis wrote in an analysis for CNN. Subs are hard to find, especially in a rocky archipelago. "The rocky floor of an inland sea like the Baltic can mask acoustic signatures," he said.
That blunts the ability of searchers in the air and on sea to identify an underwater object.
Also, the Swedish Navy and Air Force, like many European militaries, have cut back on funding for submarine defenses since the end of the Cold War, Stavridis says.
"Anti-submarine warfare was something they would have needed against the USSR during the Cold War but less so during pre-Ukrainian crisis days with Russia," he says.
Despite the increase in tourist interest in the undersea wonders near Stockholm, nothing has turned up during Schmidt's forays. "I have not done any observations myself," he says.
But others apparently have. Swedish authorities have received hundreds of reported sightings. They say they are hopeful that at least one of them is useful.