The second dinghy off the boat Easy Rider has been discovered at Masons Bay on the west coast of Stewart Island.
Nine people, including a seven-year-old boy, were on the fishing boat when it was hit by a rogue wave just over a week ago.
One man survived, four bodies were recovered and four remain missing.
Extensive air and sea searches, including a deep-sea dive inspecting the wreckage, have failed to find any trace of them.
The first dinghy was earlier found near the scene of the wreck.
Senior Sergeant Dave Raynes of the Invercargill police says the second of the two dinghies on board the vessel was discovered on Sunday morning by a light plane.
He says there are no signs anybody has been inside the dinghy.
Mr Raynes says the family has been told and an aerial search of the area was undertaken but there was no trace of anything significant.
He says no further search will be carried out unless further information comes to light.