Police have named the missing boatie who has not been seen after failing to return from taking his vessel out on Lake Wakatipu on Sunday.
Police said the man was Matthew (Matt) Charles Duncan, of Bluff, who is the owner of Painting Solutions and had been working in Queenstown.
The Police National Dive Squad is assisting with the search for the married 46-year-old.
Senior Sergeant John Fookes, of Queenstown, said divers would be searching an area from the Earnslaw slipway, where the boat Sundance II set out from about 9.30am on Sunday, to near the Bay View Rd boat ramp.
The boat had travelled "several hundred metres'' from the slipway before stopping for a period of time. It has then either drifted or made its way towards the shore, Snr Sgt Fookes said.
It was not until late on Sunday afternoon that the boat was found to be empty and the man missing.
LandSAR and Coastguard personnel searched the shoreline and lake following the discovery on Sunday night.
The search was resumed on the water, around the shoreline, and from the air on Monday.