COPENHAGEN, Denmark (AP) — An amateur-built submarine financed through crowdfunding sunk in Denmark's waters on Friday and the owner was found safe onboard, the Danish navy said. However, a Swedish journalist who had been on the vessel is reported missing.
Peter Madsen, who built the UC3 Nautilus submarine that first was launched in 2008, was taken aboard a military ship, navy spokesman Anders Damgaard said. He declined to give further details.
Footage aired on Denmark's TV2 channel showed the 46-year-old Madsen getting off what appeared to be a private boat and making a thumbs-up sign as he walked away.
"I am fine, but sad because Nautilus went down," he told Denmark's TV2 channel. Madsen said "a minor problem with a ballast tank ... turned into a major issue" that ultimately caused the vessel — considered the largest privately built submarine of its kind — to sink.
Swedish police said they are investigating the whereabouts of a missing woman who had been on the submarine at some point.
"Whether the woman was on board the submarine at the time of her disappearance is unclear," police said in a statement.
The woman was a journalist writing about Madsen and his submarine, Swedish and Danish media reported.
"He told us that the journalist who also had been on board had been dropped off Thursday evening," Damgaard told The Associated Press. "They were the only two on board yesterday."
It was the woman's boyfriend who alerted authorities the submarine was missing early Friday. Two helicopters and three ships combed the sea from Copenhagen to the Baltic Sea island of Bornholm.
The navy also encouraged members of the public with boats and sonar to search, too.
"It took about 30 seconds for Nautilus to sink, and I couldn't close any hatches or anything," Madsen said. "But I guess that was pretty good because I otherwise still would have been down there."
The ballast tank is a compartment that holds water, which is used as ballast to provide stability for a vessel.
The navy initially said the sub was "found sailing" south of Copenhagen. But Damgaard later said the 40-ton, nearly 18-meter-long (60-foot-long) submarine had sunk.
Madsen "told us he had technical problems" to explain why the submarine failed to respond to radio contact, Damgaard said.
Danish media reported police sent divers down to the submarine. There were no official comments.