Whether it's tussling for the ball, a crafty kick under the water or even outright punching and wrestling, water polo is a sport where even the girls are not blameless when it comes to playing dirty.
Played by teams of seven swimmers with a goal at each end, the high-octane sport demands supreme levels of fitness, strength and ball skills.
But the rough and tumble game is also about a sly hold here, a niggly push there to gain an unfair advantage and fox the match officials.
Greig Richardson, an assistant coach for the Australian women's team, admits there is plenty of rough stuff in the sport, first played in the Olympics in 1900 and an ever-present event at the world aquatics championships.
"It's pretty physical. I think the women's game is physical in a different way. With men it's all about power but the women do a lot of holding because of their costumes and you've got a bigger surface area to hold on to."
Canadian women's skipper Krystina Alogbo says matches can get feisty.
"In women's water polo there's a lot more (swimsuit) to grab, so you're being pressured a lot, you're being held a lot more than the men. With the men it's more physical. There are a lot of things that go on under water."
"You have to find a way out of it. Men and women aren't the same shape but when a woman hits another woman it's just as strong as a man hitting another man," she adds.
But for U.S. women's captain Brenda Villa, there is not much difference between the men's and women's games.
"They say because we have more more suit to grab that there's a lot more that goes on under water. I don't think there's that much of a difference between the men and the women."
Villa says how much physical contact is allowed depends on the match officials but insists no team is blameless.
And she admits that a canny hold here and there can influence the game. "If you have a good hold on somebody you really can control them because they just can't go anywhere. We try not to do that and there are some teams that do it less than others but I don't think there's any team out there that doesn't do it, us included."
For Australia's Aidan Roach, who plays as a driver on the Australian men's team, what goes on under the water remains a trade secret.
"There's a couple of dirty tricks, a couple of dirty shots thrown sometimes but everyone gives as good as they take I'm pretty sure. Maybe a couple of punches, some knees, maybe your cozzie (costume) gets pulled but I won't go into the finer details. It's very physical. Part of it is wrestling, it's just as much wrestling as it is swimming," he said.
Asked whether matches ever degenerate into the sort of fist fights that ice hockey is famous for, Roach said it doesn't happen much in tournament play.
"More so in training games than in official games. It gets a bit niggly sometimes. You might put one under the water. I think one of the boys today had a bloody nose but most of the boys are pretty tough and just get on with the job."
But U.S. men's captain Tony Azevedo wants to see the authorities tackle fouling to make it a better spectacle.
When asked how much goes unseen, he said: "For sure, too much. I think that's one of the faults of our sport, there's too much going on.
"It's definitely the most physical game out there and the referees don't see what's going on. It's a brutal game and in the end it's not as finessed as you'd like to see.
"You want to see some good goals and nice moves and in the end it turns out to be a boxing match."
He says technology, including underwater cameras, is available to clamp down on offenders and authorities are trying to address the problem.
But he added: "It's going to take a long time. We've got the technology, it's possible, but the rules are going to have to change."
He says the women's game faces the same problems.
"They're probably a little meaner than everybody else so I wouldn't want to be playing against them."© Agence France-Presse