The family provided a statement to the Herald today.
"The loss of Rowan has absolutely shattered our family and everyone who knew Row," they said.
"He was an incredibly positive, magical and special person who loved life and we as a family are supporting each other and Rowan's friends as we try to make sense of what has occurred."
The family had been inundated with messages about Rowan's death.
"We want to thank everyone for the overwhelming support we have received from the water polo community, New Zealand Police and our friends and family," they said.
"Kia kaha waitoa."
Rowan Brown
We are devastated to announce the death last night of Rowan Brown - one of our most talented and hard...
Posted by North Harbour Water Polo Club on Thursday, 23 January 2020
Rowan will be farewelled at a service on Wednesday at Rangitoto College.
His family have requested people wear "loud and colourful shirts, as this is what Rowan loved to wear".
After Rowan died his club paid tribute to him.
"Our hearts are breaking for Rowan's wonderful family," the post said.
The club described Rowan as "a familiar face to so many of us around the pool not only as a Rangitoto, North Harbour and NZ player but also as a passionate coach and mentor to so many in our club".
"He was a vital member of our senior men's team and a true inspiration to so many," the posting said.