The Celtics will be making their way through the streets of Boston on Duck Boats, with countless fans flooding the roadways in celebration of Banner 18.

Friday’s party, coming after Monday’s Game 5 clincher at the TD Garden over Dallas, will surely be glorious, but it means a loss of revenue for the company that provides the boats.

Boston Duck Tours has canceled all tours for the day, calling everyone who had booked an outing to either confirm the cancellation and a refund or to reschedule a trip another day. The revenue shortfall will amount to “definitely over six figures,” company CEO Cindy Brown told the Herald.

But for Brown, who has been with the company since its inception 30 years ago, the rolling rally is “all worth it” despite the monetary loss due to its global reach. Her organization averages more than 4,000 people for tours on a busy day, she said.

“Before they even won, people were saying ‘Cue the duck boats!’ and the monikers, all the memes, all the social media – it’s about our company,” Brown said standing next to boats ready to depart from the Prudential Center yesterday, temperatures sizzling.

“We were just saying ‘Can you believe that this little company has this platform to do something amazing?” she added. “Not only to be in a city that wins championships, but to be a part of the celebration is pretty special for our staff.”

The Celtics will board the boats in front of TD Garden on Causeway Street, with the parade starting at 11 a.m. They will then pass by City Hall Plaza and the Boston Common on Tremont Street before ending on Boylston Street by the Hynes Convention Center.

The parade will mark the first since after the pandemic, with the last coming in February 2019 when the Patriots won their sixth Super Bowl. In total, Boston Duck Tours has been part of all 13 rolling rallies in the past 24 years.

Gary Cormier, a man of multiple hats as a driver, narrator and captain, will be behind the wheel again Friday.

Cormier recounted how former Celtics head coach Doc Rivers brought the Big Three of Paul Pierce, Kevin Garnett and Ray Allen out on a private Duck Boat tour prior to the 2007-08 season. The purpose of the trip? To visualize what’d be like to be part of a victory parade.

As history has it, the Celtics went on to beat the Lakers in the 2008 Finals, capturing Banner 17.

“There are a bunch of emotions,” Cormier said. “I’m a huge Celtics fan and sports fan in general so you’re part of the crowd, you’re part of the people cheering, and also your responsibility to work.”

Former mayor Tom Menino came up with the idea that Duck Boats be used for championship celebrations in 2002 when the Patriots won their first Super Bowl, the foundation for the City of Champions.

“The DUCKs were a perfect fit as a victory parade vehicle,” Boston Duck Tours states on its website. “They were originally used as Army vehicles and had great back decks. This way, the players could stand on and wave to the crowds below. It was close enough to get these players right up to their fans. But, also far enough to keep them from being mobbed by the crowds.”

Mayor Michelle Wu is carrying on the tradition.

“We’re here to talk about a simple fact and process that we have here in Boston: win a championship, we throw you a parade,” Wu said Tuesday, before outlining parade safety precautions.

Roughly 16 boats took the 2008 Celtics from the Garden to Copley Square. Two flatbed trucks carried Celtics dancers, former Celtic greats, and champion trophies from past seasons. On Friday, 25 of the 28 in the entire fleet will be used, Brown said.

Players, families, coaches, front office staff and owners – the entire organization – will be taking part.

“It happens maybe once in their lifetime,” Brown said, “so if you’re doing 15 ducks, why not do 15 and let everyone enjoy the excitement?”

About 50 or 60 Boston Duck Tours staffers will be working the parade route, with one driver and deck mate on each boat.

Other workers will start preparing Thursday night around 8, cleaning the vehicles, taking seats out, putting in platforms, opening roofs and hanging banners. The effort will cease until the boats go on the road Friday morning.

The behind-the-scenes work will start up again later Friday.

“The ducks come back,” Brown said, “and they’re riddled with confetti, water bottles, and they have to be cleaned up because Saturday morning, we’re back at it, running the tours.”