No matter where the Olympic Games are held, the swimming pool is supposed to be the same: It is 50 metres long, 25 metres wide, with 10 lanes and a few million litres of water.
Wherever swimmers go, the athletes usually know exactly what's waiting for them at competitions.
Except in Rio de Janeiro.
When swimmers take their marks at these Olympics, the pool will be a rarity in the sport. And it has nothing to do with what's in the pool and everything to do with what's around it.
The Rio venue is ringed by stands on all four sides – and organizers have built those seats closer to the edge of the water than you typically see at other international pools. While most swimming venues have fans on one, two or maybe three sides, Rio has the pool completely surrounded.
This proximity will make for an entirely different experience. Swim fans are sometimes known to be a raucous bunch, but Olympic swimmers don't usually have to contend with spectators so close by – and in surround sound.
That extra roar could be the difference maker in a medal win. Or the ambient noise could trigger a false start, psych out a competitor, or drown out a key instruction from a coach. No one really knows what to expect.
"It's going to be pretty loud," Canadian swimmer Ryan Cochrane said. "That pool is exciting."
The Canadians arrived in Rio early to acclimatize themselves to the new Olympic Aquatics Centre, but there's no way to prepare for the noise. With slightly fewer than 15,000 seats, it's smaller than venues at previous Olympics, but it will feel much bigger.
"We have a bowl that goes the whole way around," Canadian team director John Atkinson said, explaining how sound could affect the competition. "You're going to have people behind you when you're on the starting block, things you have to be concerned about. There could be additional noise behind you, when the starter says, 'Take your marks,' and that is kind of something that you have to be wary about."
With front row seats as little as 10 metres from the water, and a low ceiling overhead, the building could feel more like a bubbling cauldron than a pool.
"That will create this real bowl of noise that stays in the field of play," Atkinson said. "It will be very condensed noise on you. … It's quite a unique theatre to perform in."
The venue at the 2012 London Olympics seated about 17,500, "but the ends were blank, it wasn't all the way around you," Atkinson said. Similarly, the pool for the Pan Am Games in Toronto last year had most of its seating on just two sides.
The Canadian team has been discussing the potential benefits and risks the noise could bring, but beyond discussing it, Atkinson said there is not much teams can do to ready themselves.
The pool in Rio, where Canada has a shot at the podium in a few events, will be witness to some of the most interesting moments at these Olympics, including the much-hyped return of U.S. star Michael Phelps.
Amid the cacophony, coaches and athletes from all countries will have to make strategic adjustments.
"When you're in the water and people are roaring, you hear that," Atkinson said. "It does make a difference compared to more of a sterile atmosphere where there isn't much noise coming down onto the field of play."
Some coaches develop distinctive sounds, like a bird call, to communicate with their athletes, and can be heard poolside waving their arms and letting out shrill "whoop whoop" sounds, or barking things like "Hey-ya, Hey-ya, Hey-ya" as a way to cut through the sound of thrashing water in each lane.
The signals are used to tell swimmers if they need to speed up or slow down at certain parts of the race, and the competitors can distinguish their coach's call from others. But getting those signals through to the competitors in Rio will be more difficult.
While bowled venues aren't unheard of in swimming, they are rare at such large international events – often because the diving facilities take up one end of the venue. The only comparable site Canadian swimmer Martha McCabe has experienced was at the 2014 Commonwealth Games in Glasgow, where the crowd was also close to the water and noise levels were high, but that venue had seating on only three sides of the pool.
The stadium in Rio also has a slightly steeper bank, meaning that even some of the higher seats feel perched over the competition.
"The crowd [in Rio] is going to be closer to the pool than usual," McCabe said. "It's going to be really loud in there, so I think that's pretty exciting for us."
Canadian Brittany MacLean said she likes to arrive at a venue early to get comfortable with the surroundings, such as knowing the walk she will take from the locker room to the warm-up pool, and to the starting blocks. Like many of the swimmers who have ventured into the building for training, the words "loud" came to mind.
"It's exciting to know that that atmosphere is going to be there," MacLean said. "I'm looking forward to racing in it."