Police divers are preparing to being searching the area around the Mangatapu Bridge for the driver of a van which plunged into the water following a three-vehicle crash yesterday evening.
Two work colleagues in their 20s had been in the van when it crashed at approximately 6.10pm.
A local police constable arrived at the scene and saw that the passenger had managed to free himself from the van and was in a distressed state in the water.
The officer stripped down to his underwear, jumped in and swam to assist the man.
The man disappeared under the water but then re-surfaced and the officer grabbed hold of him as they were carried by the current.
The officer managed to calm the man down and turn him on to his back.
After about half an hour focusing on flashlights being used by searchers on the shore, the officer managed to guide them to land.
Both were taken to hospital suffering from hypothermia. The police officer was discharged later last night and is now resting at home.
Two men and a woman from vehicles on the bridge were also taken to hospital with moderate injuries.
Tauranga police area commander Inspector Clifford Paxton said: "We are very, very proud of the officer's efforts; what he did was pretty outstanding.
"He evaluated the situation, believed he could make a difference, and clearly he did make a difference. I have already had members of the public call me this morning to pass on their congratulations.
"Our focus at this time, however, remains on locating the missing driver. Our thoughts are with his family and we are working to bring them news as soon as possible."
Motorists are advised to avoid the Mangatapu area. The bridge has had restricted access over night but will close again at 11am as efforts continue to find the missing man and recover the submerged vehicle. Repairs to the bridge are also required.