Nelson police have arrested a teenager they accuse of causing a large search and rescue operation, which turned out to be a hoax.
A distress call over the Nelson marine radio sparked a call-out by a rescue helicopter, the coastguard and surf rescue in Tasman Bay on Tuesday night.
Fifteen volunteers and a fishing boat joined the search after the distress call said a boat with four people aboard was in trouble.
The hoax was discovered after several hours searching.
A 16-year-old boy is being referred to Police Youth Aid.