You might not think duct tape would be the winning solution on a high-tech under water racing machine.
But Northlander and University of Auckland student Chris Walker reckons strips of black tape added to the streamlining of the human-powered submarine and helped his team capture the world title at the European International Submarine Races 2016.
Any cracks, bumps, lumps and screws on the 3m-long fibreglass hull were covered over with tape on day four of the five-day competition in England last month. Elastic straps on the foot pedals were also replaced with duct tape, enabling the pilot to put more pressure on the pedals.
Shoulder straps made from your average trailer tie-down were added as well.
The Kiwi-styled modifications boosted the craft's speed and ensured Team Taniwha completed every race, giving them the overall winners' prize.
Back in New Zealand and savouring the victory, Mr Walker said being the pilot at the controls for the first race was nerve wracking.
"It's 2 years worth of work, a team of people and the sponsors all wanting you to do well," he said.
"I was determined to just slow down and finish and get a time on the board.
After that I started visualising the course and where I could cut corners."
The 24-year-old reckons his laidback Northland attitude may have also helped him remain calm under pressure.
"Sometimes the others were freaking out and wondering why I was so laid back."
He was born in Kaitaia and attended Kaitaia College until heading off to university in the big smoke. His parents, Anne and Ian Walker, are business owners in Kaitaia. Mr Walker piloted the Taniwha over 5.5km during racing over a total of five races per day.
Mr Walker, who is studying for a doctorate in engineering, said the Taniwha mimicked the swimming action of a leather jacket fish. The fish had fins on top and bottom and a tail that moved from side to side to propel it forward. Hydraulics were used to flex the tail and rotate hydroplanes to manoeuvre the submarine. The pilot lies inside the sub facing forward holding on to the controls. Using scuba gear to breathe they propel the craft forward by pedalling.
Their biomimetic craft was driven to impressive, near record-breaking speeds - 4.7 knots.
Races consisted of travelling 100m, then completing a 50m U-turn and 100m through a slalom to the finish. Each day the slalom became more difficult requiring more accurate turns.
"It was bloody good fun," Mr Walker said.
All running repairs were done on the Taniwha in the water behind the start line. Taking the submarine out of the water meant racing was over for that day.
He said the craft was constructed during everyone's spare time and it had been so rewarding to win the title on a much smaller budget than some of the other international teams.
While there was no monetary reward there was a trophy and the pride. Eighteen teams from around the world had originally applied to compete but strict regulations meant only 11 highly tuned teams made the start line.
When asked about who got the responsibility of being the pilot, Mr Walker said a large factor that determined who was at the helm was whether they could fit inside the submarine. Also it was an advantage if the pilot was not claustrophobic.
He said they were thankful to their generous sponsors and already they had begun their next campaign which would take place in America.