Mark McCluskey's thousand-horsepower tugboat, which usually hauls oil barges all over Baltimore Harbor, is set to gently nudge and prod an especially precious vessel this afternoon: the 154-year-old sloop-of-war Constellation.
"It's like moving an egg," said McCluskey, 40, the easygoing captain of the tug Alexander Duff.
About 5:30 tonight, Baltimore's most familiar maritime treasure will make a rare getaway from its Inner Harbor berth to take part in tomorrow's commissioning of the $1.3 billion destroyer USS Sterett in South Locust Point.
It's up to McCluskey and his mates at Vane Brothers towing in Fairfield to get the sloop there and back in one piece by early Sunday. The tug operators are key players in a complex choreography featuring the Coast Guard, the Baltimore Police Department marine unit, the Navy and the Constellation Museum.
"I am always nervous as a cat when this ship is under way," said Christopher Rowsom, the museum's executive director and overall conductor of this trip. "I probably won't show it, but my eyes are on everything. I'm always watching."
Planning for the three-mile jaunt began months ago. The Coast Guard had to approve a temporary safety zone around the ship - 200 yards ahead, 100 yards in other directions - as it glides across the harbor. The Naval Sea Systems Command had to give its blessing. Although the ship was donated to the city in 1955, the Navy has oversight.
Then there are the contingency plans just in case the ship "springs a plank," as Rowsom put it. The tug could hastily make for land at a number of spots, such as Clinton Street. In the unlikely event that the 150 people aboard have to abandon ship, the Navy Operational Support Center has arranged for an open-air landing craft to trail it.
But the most hands-on job belongs to Vane Brothers, which by now knows the drill. The towing company has moved the ship for free about once a year since the mid-1990s, when Charles Hughes Sr. - whose family owns the company - sat on the Constellation Museum's board.
"It's our gift to the city," said his wife, Betsy Hughes, vice president of Vane Brothers.
The last time the Constellation, completed in 1854, traveled on its own was in 1893, when it sailed a final time after a career that included intercepting slave ships from Africa. For more than a century, it has relied on borrowed brawn. When it came to Baltimore from Newport, R.I., in 1955, it traveled via floating dry dock.
