"The family were on the second day of their tour when the tragedy occurred," Mr Lexmond said.
"Our inquiries into what happened on Wednesday indicate Mr Loh dived in on his own, after four or five other members of his tour party had made a couple of wharf jumps each."
The 37 year-old was seen swimming around in the water after he made his jump and witnesses said he seemed fine.
"Shortly after, he could be heard coughing and spluttering in the water underneath the wharf," Mr Lexmond said. "It was Mr Loh's judgement call to go into the water.
"It's not clear what might have happened to cause him to get into difficulties but he might have been caught by one of the swells going along the wharf and took on some water."
The Navy joined the search late yesterday afternoon, using an inflatable with a crew operating a remote-controlled sonar device.
"They located something in an area of interest on the sea floor yesterday afternoon and the divers will dive on that spot today," Mr Lexmond said.
The search resumed at about 8am this morning. Searchers planned to use the surf club rescue craft again and a fixed- wing aircraft would fly further along the coast and out to sea on Monday if needed.
"We remain optimistic that we can find this man and return him to his family," Mr lexmond said.
A customary rahui, banning the taking of seafood, was in place between Waihau Beach and Kaiaua Beach as a mark of respect.
-- The Gisborne Herald
