Authorities are not sure how to remove a ute found submerged in the Tauranga Harbour halfway between two islands on Sunday.
It appears the ute was caught by a rising tide while being driven from Matakana Island and Rangiwaea Island.
Bay of Plenty Regional Council senior compliance officer John Morris said the ute was found halfway between the islands.
"My guess on how it got there is someone was trying to get from Rangiwaea to Matakana."
He said removing the ute was "not going to be easy".
"We're now in the process of trying to locate the owner or person responsible for getting it stuck and are pulling a plan together for getting it out of the water.
"It's not looking like that will be able to happen from land."
It was not clear whether the vehicle had spilled any oil, as a few tides had passed through by the time the council heard about it. Morris said the focus was on removing the vehicle.
A police spokeswoman said it looked to officers who checked the ute out that it had been travelling a popular route but got stuck and caught in a rising tide.
The ute was spotted by a fisherman on Sunday afternoon.