Police say they will not charge anyone over the outdoor education trip that ended with three people drowning off the coast of New Plymouth.
Stephen Kahukaka-Gedye and Felipe Melo, both 17, were swept into the sea along with their instructor, Bryce Jourdain, in August.
They were part of a group of Spotswood College students on a rock-climbing traverse at Paritutu Rock, led by instructors from the outdoor education centre Topec.
Detective Senior Sergeant Grant Coward said the police investigation was long and detailed, and no evidence of criminality was found.
The Ministry of Business, Innovation and Employment is conducting another investigation into the tragedy.