Sonar searches of the seabed are underway during today's search for the Rotorua fisherman who has been lost at sea for at least 39 hours.
The 24-year-old fisherman was reported missing at 11.20pm on Monday after another fisherman located his two companions who had washed ashore.
The missing man's brother-in-law and 10-year-old nephew were treated and discharged from Tauranga Hospital on Tuesday.
Their vessel, a 4m aluminium dinghy, overturned as they crossed the Bowentown Bar.
Chief Petty Officer Daniel Bramley, from the Auckland-based HMNZS Matataua unit, said Navy personnel spent about three hours today sonar mapping the seabed looking for any objects of interest.
The six nautical mile area being searched and mapped was between the Bowentown Bar and where the 4m dinghy was found, which was 0.75 nautical miles north of the bar.
Search and Rescue co-ordinator Sergeant Vince Ranger said shoreline searches of Waihi Beach around the northern rocks and the Bowentown entrance would also be undertaken today, possibly around low tide.
A member of the Waihi Beach Surf Club confirmed club members would be involved in the shoreline search.
Bramley said the police dive squad was now on its way to Waihi Beach from Tauranga.