"The team all got a vote and the voting went well obviously, so I was pretty stoked with that. It's great that I'm recognised as a leader and I can pass my knowledge on to them of the world circuit."
Johnston, who will compete in the ironman, board race, tube rescue, surf race, surf teams and taplin relay over the three-day competition, is the New Zealand under-19 board race champion and ranked second in the surf swim. He was the standout performer at the Australian Pool Championships, where he picked up six individual top three medals.
He believed training in the Bay's world-class conditions, among some of the best surf athletes in the country, to be a huge advantage.
"We've got quite a few people from the Bay - it's great to see them go from the Bay team to age-group New Zealand teams. Hopefully, it'll be with the open team next."
Papamoa and New Zealand under-20 coach Kurt Wilson said the team were in good shape, despite the word championships coming at an inopportune time.
"The guys have put in some hard yards over these last winter months and incorporated a trip over to Australia for the Aussie pool champs and had a lot of local racing," Wilson said.
"The majority of the surf lifesaving movement is dormant at this time of year and these guys are getting ready for the biggest international event of their life, so there have been some challenges."
Fellow Papamoa and under-20 representative Danny Hart is also part of the team.
The 17-year-old, who will compete in the board rescue, board relay, taplin relay, board race and beach relay, came second at the board under-19 New Zealand Championships and is already rated as one of the best board paddlers in the country.
He plans to use his first international competition as a yardstick to judge himself against the best young talent surf lifesaving has to offer.
"Honestly, it's a bit of a toss up, I've got no idea how I rate," Hart said.
"Racing all the top guys in the world will be a great experience - in a new culture on different beaches and different surf, it'll be a great experience."
Natalie Peat, Lisa Carrington and Max Beattie will all represent the Bay in the New Zealand open team.