The men are missing from the Greymouth-based Wendy J, which sank on the South Westland coast and ran aground after becoming entangled in a rope.
The alarm was raised yesterday morning after someone in a light aircraft spotted wreckage and a life raft on the shore.
A survivor, Mark Thomas, was found yesterday near Teer Creek, about 10km southwest around the coast from Smoothwater Bay, the area where the boat sank.
Thomas was fishing on contract for Greymouth company Westfleet Seafoods.
Westfleet general manager John Brown told the Herald today he had spoken to Thomas, who is in his early 20s.
"He said they might have picked up a rope around the screw and it stalled the engine - a floating rope off a cray-pot or something like that."
Asked how Thomas managed to survive, he said he was tough and had a very strong will.
Thomas was taken to Grey Base Hospital in Greymouth after his ordeal and has been discharged.
The search for the missing men was suspended last night and was held up by bad weather this morning but conditions have eased and it has resumed.