The Chesapeake cowboys rode into St. Michael’s, Md., on a steamy Sunday in August, and the air smelled like crab seasoning and diesel exhaust, with a dash of light beer and lime.

A couple thousand spectators had gathered in the Colonial-era tourist town on the Eastern Shore of Maryland, about 80 miles east of Washington, D.C., to watch the cowboys square off in a competition unique to the Chesapeake Bay: boat docking.

Fans crammed into hot bleachers overlooking the Miles River. They stood elbow to elbow on a lighthouse deck. A few brave onlookers balanced, precariously, atop dock pilings without spilling their drinks.

A D.J. played a love song to “long-neck, ice- cold beer.”

“It’s redneck like NASCAR, just on the water,” one competitor, Ronnie Reiss, known as “Reissy Cup,” said on his boat, the May Worm.

After a prayer for safety and a recording of Chris Stapleton’s “Star-Spangled Banner,” a woman yelled “start your engines” into a microphone. The crab and oyster boats, known as “deadrises” for how they handle the shallow Chesapeake Bay, grumbled to life.

For the next two hours, fans shouted and flinched as boats with names like the Nauti Girl, Outlaw and Hard to Handle reversed out of their slips in a cloud of black smoke.

“The louder you yell, the faster they’ll go,” said the M.C., Erik Emely, known as “Flea,” his Eastern Shore drawl sounding almost Southern.

The annual boat-docking competition at the Chesapeake Bay Maritime Museum is part of a circuit that travels to about 10 towns in mostly rural shoreline areas in Maryland and Virginia in August and September. The first event was held in 1971, born, as a video from ChesapeakeStory.com surmises, “out of the watermen’s innate urge to turn everything into a competition.”

Mr. Emely said: “It was about watermen yapping on their radios saying I can tie up faster than you. It was just all bragging rights. The only thing they’d win or bet back then was a tray of soft crabs.”

Today, winners can collect thousands in a day or some fuel money to get home. Pride’s still on the line, too.

Each pilot competes, alone or with teammates, against a running clock. It’s like extreme parking with some rodeo at the end.

After clearing their boat slips, competitors throttle forward and turn hard, kicking up a swell that sometimes wets the fans. (It was 90 degrees by noon in St. Michael’s, so no one cared.) The boaters reverse hard, again, backing into another narrow slip by the bleachers at full tilt. The boats, ideally, come to a stop inches from the bulkhead, then the captains scramble to lasso two lines to the pilings.

The competitor who does it fastest, wins.

“I like to think that we’re a show, so no one really loses,” said John Ashton, captain of Miss Julie.

Sometimes the boats hit pilings. Sometimes they don’t stop. The crowd gets a kick out of any mishap.

“We crash all the time,” said Jake Jacobs, who captains Outlaw, one of the bay’s faster boats. “If it crosses your mind that you might scratch your boat, you done lost. You can’t be scared to hurt your boat.”

Mr. Jacobs, 37, won two categories in St. Michael’s, hoisting trophies and a Corona at day’s end. He said he could win about $10,000 in a season. His boat and a handful of others have sponsors, many of them landscaping or construction companies.

“Some of us local businesses like to help, whether it’s $500 to slap a small sticker on the boat or a tank of gas to get them to the competition,” said Jason Murphy, whose company name, Peake Contracting, was displayed on Mr. Reiss’s May Worm.

The cowboys — the name competitors coined when unsuccessfully vying for a reality show more than a decade ago — had been in Cape Charles, Va., a week earlier. A few competitions remain for the season: Solomons Island, on the Western Shore of Maryland, and Tilghman Island, across the bay.

The fan favorite, up and down the bay, is Mr. Reiss’s daughter, Peyton Reiss, who is 9 and sports turquoise braces. She competes in kid’s categories, if there is one, but more often against adults, pumping her fists at the families in the bleachers.

The writer James A. Michener, who lived in St. Michael’s for several years, once described Chesapeake watermen as “quiet heroes, echoes of that day long distant when most Americans made their living close to nature.” Some of the competitions are celebrations of that waterman heritage.

Others, like Salisbury’s Extreme Boat Docking Competition in Salisbury, Md., which takes place at a bar on the Wicomico River, are more of a party, and last all weekend.

On another hot August Sunday, down the bay from St. Michael’s in rural Dorchester County, fans converged on the Slaughter Creek Marina for the Taylors Island Boat Docking Challenge. They parked on the shoulders of a two-lane road with marshes and farmland in every direction. Attendees at the St. Michael’s event donated thousands to help a competitor with testicular cancer; at the Taylors Island competition, proceeds from tickets and refreshments — about $22,000 last year — went to the small town’s volunteer fire department.

In quaint St. Michael’s, there were some sailboats, pastel polos and boat shoes. The vibe in Taylors Island — Orioles caps, camouflage Crocs or rubber fishing boots — was a bit more country.

Organizers ordered 150 cases of beer, but many attendees lined up for an “Orange Crush,” a Maryland shore staple made of orange vodka, triple sec, Sprite and — fans on Taylors Island were adamant about this — fresh-squeezed orange juice. A bartender at the crush tent there, a native New Yorker who never heard of the drink before moving to the Eastern Shore in 2005, said he’d poured hundreds before noon.

Many attendees compared the competition and atmosphere to NASCAR. Others mentioned tractor pulls and rodeos, all competitions rooted in real-world livelihoods. (Many of NASCAR’s early racers were moonshine runners, honing their skills against the police on backwoods roads during Prohibition.)

For now, docking isn’t on television, and the unique design of those Chesapeake Bay deadrises — the official state boat of Virginia — will likely keep competitions local.

But docking competitions have been discovered by a slice of social media that’s seemingly obsessed with all things boating, and some posts get millions of views.

The Chesapeake Bay even has a social media star who has gone worldwide. Luke McFadden, a first-generation waterman from the Western Shore of Maryland, chronicles the working life for his 1.6 million TikTok followers. Mr. McFadden, 27, teaches viewers how to steam crabs in one video, how to handle a crab pinch in another: “Do not yank on it,” he instructs.

He was hounded for pictures and handed free beers at the St. Michael’s competition.

“People think of boats and they think of a yacht,” Mr. McFadden said. “This is like the true grit, what boats were originally intended for.”

Many longtime competitors, like Mr. Ashton, 50, still work on the bay. But the number of licensed watermen has dropped over time.

A 2016 study from the Federal Reserve Bank of Richmond said stricter government regulations and an aging work force play a role in the decline. Seafood industry executives on the bay say they need more migrant workers to process crabs. Watchdogs say those migrants, most of them women from Mexico, are treated poorly.

Mr. Ashton’s grandparents cooked and sold crabs on Hoopers Island, but the watermen’s life may end with him.

“None of my boys are interested in it,” he said.

Mr. Reiss works in marine construction but still oysters in the winter. Peyton, his 9-year-old protégé, wants to be an engineer. Mr. Jacobs worked on a tugboat in Baltimore Harbor after high school but left the water for what he called a steadier life driving a fuel truck. (Some competitions won’t let him enter his boat for that reason.) Mr. Jacobs said the costs of being a waterman — fuel, bait, the whims of the crab market and lack of help — “never added up.”

Some watermen have outfitted their boats for tours instead, or turned them into water taxis. Others have sold them off. In St. Michael’s, a woman recognized her mother’s name in red letters on the hull of the Kathy Marie, a working boat, and began to cry. The captain of the boat hopped off to hug her.

“That was my daddy’s boat,” she told him.

Mr. Jacobs said the prize money helps because he spends so much fine-tuning his boat. Trophies are nice, too. But more than that, the competitions help him turn back time, and even if it’s just a few summer Sundays, that’s worth something he can’t count or carry.

“I’ll always be a waterman, that won’t never change.” he said “I’m a waterman with a cowboy heart.”