WASHINGTON — On a warm Friday afternoon, there's nothing quite as tranquil as a lazy cruise through D.C. that lets you look at historic buildings from a new angle while enjoying the slight breeze and the feeling of being on the water. Or thinking about what this part of Georgetown must have smelled like in 1858 when, as our guide put it, there were "thousands of mules pooping up and down the towpath" we were moving alongside, causing all the kids aboard — and a good number of adults — to laugh out loud.

Welcome to the Georgetown Heritage, an 80-foot-long tour vessel launched last year and the first boat to carry visitors through Georgetown's stretch of the C&O Canal for more than a decade. Over the course of an hour, it ferries passengers on a journey stretching just over a mile, from the canal's visitors center on Thomas Jefferson Street NW to a basin on the other side of the Whitehurst Freeway, and back. (Sadly for longtime canal fans, there are no mules, which ceased to pull boats on the Georgetown stretch of the canal in 2010.)

The long, flat-topped boat is lined with wooden benches and has open sides with no windows, making it easier to take pictures, as long as you're careful: "We had a couple of iPhones go into the water last year because people were hanging their arms outside of the boats," our guide says during his safety spiel. "That's almost as bad as a personal injury, right?"

We move through Georgetown at about two miles an hour — a pace that allows kids on the towpath to run along (and eventually outpace) the boat, but also gives us time to admire the bricked-up windows and old pulleys on the converted warehouses that line the canal and to think about how, before these buildings were offices and condos with water views, they buzzed with activity, loading and unloading cargo.

The first section of the canal opened to boat traffic in 1830, and construction finished in 1850. As they cruise, visitors learn about the backbreaking work, done mainly by immigrants, to construct the canal, and get to handle drill bits and tools similar to those used. But they hear about much more than the canal itself: There's a dramatic reading from the autobiography of James Curry, who used the towpath to escape slavery; diary excerpts that explain what families who worked on the canal would have eaten (lots of eels and turtles — "eeeew!"); and a poem written by a member of the Civilian Conservation Corps, a government program that restored sections of the derelict canal during the Great Depression.

This history lesson is interactive, which leads to surprises: The guide asks the crowd to imagine the names of some of the captains who piloted barges on the canal in the 1800s. "Josiah!" "Horace!" people on the benches shout, before the host asks, "What about Kate? Or Nancy?" and begins reading names of women who were captains or worked as lock keepers. (I'm not surprised to learn afterward that the script from which guides read was developed with field trips in mind, "so a lot of the information that folks will hear on the tour is tied to public school standards," says S. Rex Carnegie, Georgetown Heritage's director of education and partnerships.)

It's a placid journey down and back, with views of ducks swimming and a stellar, surprisingly green view of Rosslyn, Va., and the Key Bridge at the end of the first leg, which should be your cue to switch sides on the boat and enjoy some different scenery on the ride back.

The one exception to this otherwise relaxing voyage is the trip through a lock, which marks either the start or end of each tour. The C&O Canal runs 184.5 miles between Georgetown and Cumberland, Md., and over the course of the journey, the elevation climbs more than 600 feet. To help boats ascend, they enter 74 locks, a series of chambers that act like steps along the towpath. As the Georgetown Heritage enters a lock and a gate closes behind it, water rushes in. The flow causes the boat to sway from side to side, slamming into the stone walls as the water level — and the boat — rise higher, much to the excited delight and "WHOA!"s of younger passengers.

For Carnegie, these explorations of Georgetown are personal: "I grew up here, and I never even knew that there was a canal boat program," he says. "I'm sure there are a lot of people throughout the city who don't even know that there's a canal, let alone that they can take a boat. We want folks all over the city to feel like the canal belongs to them, just as much as it belongs to the folks in Georgetown."

The Georgetown Heritage's return this year was a pleasant surprise, since the other Georgetown Heritage — the community organization behind the boat — had announced last fall that tours were going to be suspended, probably until 2025, because the canal needed to be drained "for an estimated 30 months to allow for a major restoration of Locks 1, 2, and 5, as well as critical valve and wall repairs."

That vital work "has not been pushed back or rescheduled," explains Christiana Hanson, the chief of interpretation, education and volunteers for the Chesapeake & Ohio Canal National Historical Park. Instead, the National Park Service is "going through the normal solicitation and preparation process for large-scale projects," and a vendor for the work is expected to be chosen this year. "We don't have a specific date for rehabilitation work beginning at this time," Hanson says, "though there is a possibility that its start will mean a shorter boat season."

That's your cue to set aside some time — maybe a lazy weekend jaunt or a midweek afternoon excursion with the kids — before the chance dries up.