A SWAT team boarded a ferry that had been set adrift off Seattle, Wash. and arrested the man who allegedly stole the vessel earlier Sunday morning.

The boat, the Victoria Clipper IV, was first spotted unmoored, and apparently unmanned, 300 yards off Pier 69 in the Seattle waterfront at around 7 a.m. PT.

When a tugboat crew attempted to secure the boat, they discovered there was a man on board.

"Knowing that no one had permission to be on the boat, we used our marine unit, our bomb squad, we used our SWAT team and hostage negotiators, all in partnership with the Port of Seattle and the United States Coast Guard, to pretty much isolate the incident, contain the ship, and bring it to a peaceful resolution," said Seattle police Sgt. Sean Whitcomb.

At 10:24 a.m. police confirmed they had reached the boat and made contact with the man on board.

The Seattle Police Department tweeted this photo of the Victoria Clipper adrift, with a tugboat nearby, in Elliott Bay Sunday morning at 10:10 a.m. PT (Seattle Police Department)

After brief negotiations, a police tactical team boarded and arrested him without incident.

"Apparently, the gentleman who was on board the boat somehow set it adrift," Whitcomb said. "It's just one of those really zany incidents, and we're just glad it turned out to be as benign as it did and that we were able to bring things to a successful resolution as quickly as we did."

Police are still working to determine how the man was able to commandeer the ship, and exactly why he did so.

"[He] apparently wanted to take it across Elliott Bay to West Seattle, which is never recommended. There's plenty of other modes of transportation in order to meet those needs, and of course he's going to get booked into King County Jail after we're done questioning him," Whitcomb said.

The man is facing yet-to-be-determined charges of either piracy or grand theft vessel.

The Victoria Clipper IV, a 130-foot-long passenger ferry that operates daily service between Seattle and Victoria, B.C., is being towed back to port, where it will undergo a full inspection.