The extra crew members are collected and dropped off from a support boat that follows their waka closely.
The heat and sometimes big waves test all the paddlers.
Over the years Northland junior and senior teams have collected medals but this year with the return of the world-class Tahitian paddlers the silverware may be harder to collect.
This year a regional squad of J19 girls will leave their final NCEA exams behind when they board a flight to Rarotonga .
Due to sports, kapa haka and school engagements the girls have only had three full team trainings but have been coached in their local waters at Lake Ngatu, Taipa, Tapuatahi, Te Tii, Tutukaka and Onerahi.
Coach Hilda Halkyard-Harawira said the biggest challenge for the girls would be the heat and good hydration before and during the race.
About 300 juniors from around the Pacific are expected to compete in 12km and 500m sprints.
Experienced paddler Ani Wetere, of the Mitamitaga Club, is looking forward to her seventh Vaka Eiva.
She said she had never paddled in flat waters for the round the island race.
One year conditions were so rough paddlers reached a marker half way round the island then turned back as the waves were too big.
"Paddling round the island is a highlight.
"It's such an achievement to get round."
She said her team was looking forward to warm water in Rarotonga after practising changes in cold water off Tutukaka.
Wetere said the camaraderie between paddlers was amazing and after seven years at the event she had made friends from around the world.
