On a rainy night at the Northcote College school pool, two teams of five are shuffling kayaks into the water and readying themselves under suspended goals. The whistle blows and right away one player gives another a hard shove, knocking him underwater.
He rights himself in seconds and is off down the pool with the ball cleverly placed on his paddle before flicking it to a teammate. The boats are like floating bumper cars as they furiously fight for possession. It's an exciting, fast-paced game to watch, with many goals scored.
Canoe polo, which is a combination of water polo, basketball and kayaking, is thought to have begun in 1880 in Scotland with men sitting on wooden barrels fitted with saddle cloths playing ball in the water. The players used a feathered style of wooden paddles and early sketches make it look like a water-based game of equestrian polo.
Just over 100 years later, the rules of modern canoe polo were merged into one standard style. Today, it's the fastest growing discipline of the International Canoe Federation.
"It's not well-known, but kids love it," says Grant Briden, whose son Jack (14) started playing after watching the Olympic canoe events on television.
"The first skill they learn is to right themselves - it's always a challenge but easier in the smaller kayaks," says Briden, who tells me the specialised polo kayaks are lighter and faster than ordinary kayaks and the players need to wear helmets and faceguards.
The school teams I'm watching are mixed and the national women's team, the Paddle Ferns, is ranked fourth in the world. The men's Paddle Blacks are 13th in the world.
"I like it because it's a team game and everyone develops together," says 15-year-old Ruby Beadle, who signed up to play because her friend's dad is the coach. "I was a bit intimidated by the guys at first, but I don't get left behind and didn't need any skills when I started."
Andrew Candy, northern regional co-ordinator for the Canoe Polo Schools Council says: "The sport teaches skills transferable to other kayaking disciplines such as surf-ski racing and whitewater kayak."
"It looks very aggressive," admits Candy, as a spray of water hits me on the sidelines. "But it's actually very tightly controlled and disciplined."
Candy was previously a water polo coach. He says water polo "is one of the more insidious sports around because it's very rough and physical". However, he took his water polo players to watch canoe polo and they said: "This is mad!"
Canoe polo is an equipment-based sport with strict rules around the use of paddles, with no tolerance for using them against anyone. There's also a strong emphasis on sportsmanship.
"It's not for everyone because it's quite physical," says Candy, "But these kids find it really exciting. It's rewarding to see how much fun the kids have with canoe polo."
Alex Hunt (16) also likes the team co-operation element: "We have to talk to each other a lot, that really helps, so I've learned communication skills and working as a team to score a goal.
"At first, I was intrigued that you got to be in a boat and in a pool at the same time. It gets quite tight and we're all clumped together."
He tells me the senior players are allowed to push each other over in the kayaks if they know each other, but are not allowed to push the juniors in case they don't know how to roll properly.
I start to worry about their fingers getting stuck between the kayaks but Hunt tells me a red card is given if the fingers are hit. Pushing someone when they're close to the side of the pool is also not allowed.
"I once broke my finger, but we all wear helmets to protect our heads and our legs are obviously safe in the kayaks," says Hunt. "Like any sport, if people know what they're doing it's okay and then we all get along fine."
In a world filled with non-contact sports, it's interesting to see how much the kids are enjoying the physical side of canoe polo.
They're having fun, pushing each other around a bit, but being good sports.
Expect big things from these kids and this sport in the future.