A member of the Horouta Waka Hoe Club in Gisborne, she contributed to the sport as an elite paddler and coach, and recently joined the board of Waka Ama New Zealand.
The organisation announced her death on Facebook on Saturday evening.
The wider waka ama whānau was "devastated" by Campbell's death, the post said.
"Kiwi has impacted thousands of people in our sport and her community in Tairāwhiti. Kiwi's dedication & commitment to our rangatahi was awe inspiring, she held them close to her heart and worked tirelessly to expand their horizons throughout Te Moananui a Kiwa and offer them opportunities they otherwise may not have had.
"There are so many ways to describe Kiwi, she was exceptional in the true sense of the word. She was formidable, her strength and determination unsurpassed and core to her success.
"Kiwi will leave a legacy for all those she paddled with, coached, mentored and befriended. We have all been enriched by her presence in our waka ama whānau."
Waka Ama New Zealand extended its sympathies to Campbell's husband Bruce, himself an international medaller, sons Mairangi and Maia, who are both gunning national representatives, and mother Irene.
"Our hearts are breaking, and we share the pain and depth of your grief."
Campbell was twice named Sports Coach of the Year at the Māori Sports Awards.
In 2020, she was inducted into Waka Ama New Zealand's virtual hall of fame for her contribution to the sport.
Her home club has asked paddlers to keep off Tairāwhiti waters until further notice.
A post on behalf of Campbell's whānau said her death was "sudden and untimely".
Her body would be examined by the coroner on Saturday evening, the post said.
Black Ferns Sevens player Kelsey Teneti said in a Facebook post that her former waka ama coach was "one of the best coaches" she had ever had.
"You gave me the mindset of a fighter, a champion, and for that, I'll always be grateful," Teneti wrote.
