High Tide in Dorchester_16 Minute Version from Chesapeake Bay Journal on Vimeo.

Though it begins with aerial shots of the seemingly endless tidal marshes in Maryland’s Dorchester County, the latest Bay Journal documentary is about a fast-approaching future in which that landscape could be entirely underwater.

High Tide in Dorchester is the second collaboration between Bay Journal columnist Tom Horton, Bay Journal photographer and videographer Dave Harp and environmental filmmaker Sandy Cannon-Brown. The same crew produced the documentary Beautiful Swimmers Revisited in 2015, also sponsored by the Bay Journal.

A preview of the new film will take place at a public screening at at 7 p.m. on Feb. 21 at Salisbury University in Wicomico County, followed by an official debut on March 22 at the Environmental Film Festival in Washington, DC.

High Tide starts with the image that inspired it: Horton standing waist-deep in water — in what was once a field outside his father’s hunting cabin on the Honga River, where he played baseball as a child. That field is long gone, as are thousands of acres of land that have been lost in recent decades to a mixture of rising seas, erosion and high tides across the county.

If the consequences of climate change “seem a little hazy to you,” Horton says near the film’s start, “come take a tour of Dorchester County — where the future is now.”

The film introduces viewers to residents, scientists, public officials and a cemetery manager who are dealing with the aftermath of rising seas on a landscape that is changing right before their eyes. Horton calls Dorchester County “the rural Ground Zero” of sea level rise in the Chesapeake, where climate change is leaving a mark -- not in 25 or 50 years, but now.

“Essentially, that future that we’ve been scaring you with — it’s here now in lower Dorchester,” he said.

Rising seas, the film reveals, have already left their mark in places like Blackwater National Wildlife Refuge, where saltwater intrusion has left only the spindly, ghostlike stumps of former forests behind. Erosion in another part of the county has unearthed a cemetery’s tombstones and placed some of its markers underwater. The film shows fish swimming over the headstones. Roads in Dorchester are frequently too flooded to use. One resident raised his home more than seven feet off the ground last year in his determination to stay.

Though the numbers are startling — projections suggest that half of the remaining land in Maryland’s fourth-largest county will be underwater in a century — the scenes portrayed across the screen lend them gravitas.

These moments, which come and go with the tides, were more easily captured because of the film crew’s proximity. Harp lives in Dorchester County, and he and Horton spend a considerable amount of time there reporting stories for the Bay Journal, making them fitting guides for the film.

“At one point, I said, ‘We might as well make a film. We’re out here all the time anyway,’” Horton said.

Though they’re familiar with the landscape, Horton said they learned to listen to the people they interviewed, to understand how different —yet similar — local views are about the changes taking place. While scientists interviewed in the film might refer to those changes as sea level rise, others simply see erosion. Horton said they tried to convey that the cause is, in many ways, all of the above.

“You hear people say, ‘I don’t know if the sea level is coming up, but I know we’ve got tide on the land more than we used to,’” he said. “A lot of times we’re saying the same thing in different languages.”

The filmmakers and their sponsors, including the Town Creek Foundation, Shared Earth Foundation and other donors, want to see the documentary used as an educational tool to spur discussions about sea level rise.

After the film is officially released, groups are encouraged to contact the producers to arrange viewings and discussion sessions. For information, visit the film’s website at hightidedorchester.org.