New Zealand are double world underwater hockey champions after winning the men's and women's titles in Canada.

The women's team - world titleholders in 2013 - edged out Great Britain in the final in Quebec City on Saturday (Sunday morning NZ time) and then watched as the men completed the double with a 3-0 shutout of France.

Both New Zealand teams - who pay their own way to world events - went through the world championships unbeaten despite encountering deeper water than their home pools.

Iain Curtain/Facebook The world champion New Zealand women's underwater hockey team sing the national anthem before the men's final - also won by New Zealand.

They won all their round robin games to progress straight to the quarterfinals where the men beat the United States and the women triumphed over host nation Canada.

READ MORE: Underwater hockey team aim to emulate All Blacks

The women's team beat South Africa 6-3 in the semifinals after goals by Leah Chamberlin-Gunn, Rachel Arbuckle (2), Claire George, and two penalty goals awarded for fouls by the defensive team.

GILL ALCOCK Some members of this 2016 New Zealand women's underwater hockey team - including captain Claire George (second left in front row) have won the 2018 world title in Canada.

Nick Healy, Hamish Arthur and Jesse Hocking scored in the men's team's 3-1 semifinal win over Turkey.

The New Zealand women were silver medallists at the 2016 world championships in South Africa where the men finished fifth.

Captain George, vice captain Emma Rae, Paige Morgan and Chamberlin-Gunn had competed at previous world championships while Arbuckle, Rachel Colquhoun, Christie Whitehead, Rebecca Gatland, Grace McGaw, Abby Vorstermans, Emma Bavelaar and Gabi Steer were first-time players and now gold medallists. Rebecca Brosnan was the women's team coach.

Eight Kiwi men - captain Rob Tinkler, Brendan Maxwell, Liam Watson, Hocking, Jeremy Webster, Andrew Gunn, Andre Heller and Healy had previous world championships experience with Ed Firth, Hamish Arthur, Andrew Harris and Ben Paviour-Smith the new caps. Benson Taylor coached the men's team.

Trials began 18 months ago and the squads were selected last Easter with training camps held every five to six weeks.

Players were required to fund their own travel to Canada.

Underwater Hockey New Zealand chef de mission Sarah Arnold was proud of the teams' success in after facing several challenges.

"The pool depth in Quebec is three metres whereas New Zealand pools are two. Teams arrived a week before tournament so they could practice in the deeper pool.

"The heat was a challenge - most days in the high 20s with the hottest day reaching 34.

"We arrived at the accommodation on Friday [July 13] to find there was no fridge, cooking stuff, utensils, cutlery or plates. By Sunday, we had a fully functioning kitchen."

The New Zealand teams were cheered on by the largest supporters group at the tournament.

Underwater hockey was invented in the 1950s as a winter-time fitness activity for scuba divers.

World championships have been held since 1980.

Players enter the water with mask and snorkel, large fins, thick gloves to push themselves off the pool floor and a bat to sweep the puck up and over their competitors.

Games are played in two 15-minute halves.

The aim is to get the 1.5kg lead puck into the opposition's three-metre long goal tray. A non-contact sport relies on skill, speed, manoeuvreability and good breath hold.