When dawn breaks Sunday over the Tennessee River and more than 3,000 athletes dive into its chilling waters, Chattanooga's year of the Ironman will be upon us.
East Tennessee's outdoor mecca will be the first city in the world to host a full Ironman, an Ironman 70.3 (half the distance of a full Ironman triathlon) and both the men's and women's Ironman 70.3 World Championships in the same calendar year under their current format as four separate events.
"We're on the international stage with these world championships," Chattanooga Sports Committee President Tim Morgan said.
Chattanooga has been a premier Ironman destination since the organization held its first event in the city in 2014. It since has added Ironman 70.3 and was the top choice for race organizers when they decided to rotate the world championships back through the U.S.
The Scenic City's beauty and history of hosting successful events certainly played into that decision. It received top Ironman 70.3 honors earlier this year when it was named "Best Race Venue Experience," "Best Host City Experience" and placed high in a handful of other categories.
"Every city is unique, but we have such a great relationship with Chattanooga that it just made sense to bring the world championship to Chattanooga," Ironman Regional Director Audra Tassone said. "There's just so much to offer, but the community is incredibly supportive."
While there are several other cities in North America with a similar pedigree when it comes to outdoor events, there was something in particular Chattanooga offered: Southern hospitality.
"[Chattanooga and North Georgia] are a very welcoming community, and that's why we loved being there," Tassone said.
That hospitality manifested itself time after time as thousands of volunteers continued to warmly welcome competitors and help them on race days.
Each of the events requires hundreds of volunteers, and the Volunteer State has lived up to its name.
"I think a lot of [what makes Chattanooga an ideal Ironman location] has to do with the volunteers." Chattanooga Triathlon Club President Billy Day said. "We've got four different Ironman events this year, and I think that's because of the number of volunteers we've had these last several years."
What is likely one of Chattanooga's biggest outdoor years to date will begin with some familiarity.
The local Ironman calendar starts as it has for several years, with Ironman 70.3 on Sunday and the Ironkid's race Saturday at 9 a.m. on Riverfront Parkway.
Many athletes and spectators have long planned for this particular race, as they will flock to the city to preview September's world championships.
Sunday's route will differ from the world championships — which offers a more strenuous course — but racers will test a large portion of the route and familiarize themselves with the city.
The route will still start and end in Chattanooga while snaking through Walker County in North Georgia. Ironman Village will remain along the river at Ross's Landing, and free transportation will be available through the city's shuttle system.
Chattanooga officials encourage spectators and visitors to park in the lots and garages throughout the city and use the free electric shuttle and the Bike Chattanooga system.
The shuttle service will extend its hours and open Sunday at 5 a.m. Extra shuttles also will be running to account for the expected crowds.
For those on the water, the Tennessee River between Ross's Landing and River Mile 469 behind the Boathouse Restaurant will be closed to pleasure boats.
However, spectators can ride their own bikes to the event and use Chattanooga's bike lanes and cyclist-friendly downtown area.
The familiarity of Sunday's race extends beyond just the city and route.
Chattanooga's 2016 women's Ironman 70.3 champion Heather Jackson returns to attempt a second consecutive victory in the city.
The American will don race number 41, the highest of any female competitor.
"Chattanooga was one of my favorite races last year! The town is just big enough, but still has that small town feel with great restaurants and pubs and where everyone talks to you," Jackson wrote for an article on Ironman.com. "As a race venue, it was great because everything is centered around one area."
The men's race is guaranteed a new champion.
Neither of the two previous winners – Sebastian Kienle last year and Andy Potts in 2015 – return. The highest returning finisher from 2016 is American Justin Park, who finished fourth.
Spectators will be able to watch the race from just about anywhere along the course. Chattanooga's bridges offer a sweeping view of the swimming leg, while Chickamauga and other parts of North Georgia give crowds an up-close view of the cycling route. A crowd favorite comes during the final leg – the run – when spectators will gather on Barton Avenue for a laid-back, party-like atmosphere as the athletes struggle through the hills.
The Ironman 70.3 World Championships return to North America with the Sept. 9-10 race taking place in Chattanooga.
After its 2006 inception, the 70.3 world championships were held in Clearwater, Fla., until 2011 when they left for a more challenging course in Nevada before spending three years abroad in Quebec, Austria and Australia.
Racers won't have to worry about whether the smaller new kid on the block can pack a punch.
Race organizers made sure the course hits early and hits hard.
"A championship course is defined by the hard level that really orchestrates the competition," Morgan said.
Instead of the usual downstream swim that makes its way to Ross's Landing, world championship competitors will start at the landing, swim across the river before turning and swimming more than 800 meters against the current and then loop back to the start.
Once racers have completed the swim, they will hop on their bikes and head out on the usual Ironman path, but the torture doesn't end with the swim.
Five miles south of town, competitors will take a turn onto Ochs Highway and climb Lookout Mountain.
"The world championship courses are always hard as heck," said Chattanooga Triathlon Club member Todd Viens. "It's really going to be a challenge, but I think people will be up for it, and there's a lot to see; a lot of beauty on the course."
Racers will see much of the region's renowned beauty.
Chattanooga offers its riverfront and downtown area leading to Lookout Mountain that will take riders into Georgia to see more mountains, open land and Walker County's scenic views.
Viens, who will be competing Sunday, competed in last year's world championship in Australia. He believes the area's scenic nature, the course's toughness and the climb up Lookout Mountain will brand Chattanooga in the minds of many international athletes and their families.
"I think people are going to be surprised when they see our little town," he said. "Most people probably haven't heard of Chattanooga, but they're certainly going to remember it after they finish the race."
Morgan hopes he can capitalize on that opportunity.
"I can assure you that there are partners across the board inside Hamilton County and inside Walker County that will define the success of these world championships," he said. "Which will hopefully bring [Ironman organizers] back to both of our counties to spend more time, more money and potentially even relocate down the road."
Contact Mark Pace at email@example.com or 423-757-6361. Follow him on Twitter @themarkpace.