Last year, Nico Wildbore, 17, tragically lost his sister Bethany to suspected suicide.
Every kilometre he swam, marked a year Bethany lived.
As part of World Suicide Prevention Day, Nico swam nearly nine hours straight to fight the stigma tied to discussing mental health and suicide.
Nico said thinking about sister helped push him to meet his goal.
The challenge was even greater for the Cashmere High School student, who was born with a type of cerebral palsy called hemiplegia. It meant he undertook the swim with limited mobility in his right arm and leg.
Between 9.30am - 6.30pm, Nico had only three 20 minute breaks.
It is estimated with the number of donations he made on the day and with further funds to come through he will raise about $10,000 for the New Zealand Mental Health Foundation.
Nico said he was feeling tired at the end of the challenge but happy he had finished what he started and he had "so much support".
The swim was held at the Waitaha Swim Club, based at the Canterbury Swim School in Hornby.
Nico's mother Keiran Horne said he showed immense "strength of character".
"He not only finished the 16km but he finished with a smile on his face. I was immensely proud of him. It was awesome," she said.
Ms Horne said the swim club had an instructor swimming alongside him all day and his coach encouraged him every step of the way.
His friends jumped in the pool to help give him support too, she said.
"There was always somebody swimming alongside him in the other lane which helped him along," she said.
Ms Horne said she was "flabbergasted" at how well Nico went but the exhaustion "really hit him" in the evening.
•To support Nico's effort donations can be made at the Givealittle page https://givealittle.co.nz/fundraiser/nicos-16-kilometer-swim.
Where to get help:
If you are worried about your own or someone else’s mental health, visit your GP or local mental health provider. However, if you or someone else is in danger or endangering others, call police immediately on 111.
Or if you need someone to talk to phone:
•LIFELINE: 0800 543 354 (available 24/7)
•SUICIDE CRISIS HELPLINE: 0508 828 865 (0508 TAUTOKO) (available 24/7)
•YOUTHLINE: 0800 376 633
•NEED TO TALK? Free call or text 1737 (available 24/7)
•KIDSLINE: 0800 543 754 (available 24/7)
•WHATSUP: 0800 942 8787 (1pm to 11pm)
•DEPRESSION HELPLINE: 0800 111 757
