A van with eight members of the visiting team inside was rammed and shot at while being pursued by up to four vehicles.
The man was reported missing from fishing vessel Pacific Challenger on Monday night, about 11km offshore.
Maritime NZ's Rescue Coordination Centre is coordinating the search, assisted by rescue helicopters from around the North Island.
Police say there are still a number of unanswered questions.
The Serious Crash Unit and WorkSafe have been notified.
The six-day event is the biggest of its kind in Australasia.
Category 3 homeowners won't have to contribute towards home demolitions, councillors agreed on Tuesday.
Mental health support in Hawke's Bay is scarce and the region has relatively high levels of self-harm and suicidality.
Panicked locals have been stocking up on their water supply.
