A lifeboat and other items from the trawler were found by search and rescue personnel, but the boat's three crewmen - fishermen Jared Reese Husband, 47, of Timaru, Paul Russell Bennett, 35, of Motueka, and Terry Donald Booth, 55, of Nelson - remained missing, presumed dead.
Divers were expected to return to the wreck today to bring home the body of the remaining fisherman.
Efforts were hampered yesterday by poor weather conditions and the depth of the water - the wreck is sitting 40m below the surface, and divers could only carry out a fixed number of dives in one day, police said yesterday.
Tim Burfoot, chief investigating officer at the Transport Accident Investigation Commission (TAIC), said one of its investigators would accompany the Navy divers as they searched the wreck for the remaining man, and for clues as to why the vessel sank.
"The divers, when they go down there, have cameras on them and that is recorded on the vessel above to be guided to certain areas of interest," he told Radio New Zealand.
They would be looking for "anything that can give us a clue as to what would cause the vessel to sink", he said, including the systems on the boat, and parts of the ship where water could get in, such as the hatches.
Nothing that could hint to what happened had been found yet, Mr Burfoot told the broadcaster.
"We've been able to confirm the status of about two or three of the items of interest, but no clues yet as to what might have caused the sinking."
He added: "It's still very early in the inquiry. It has its special challenges when we don't have ready access to the vessel or the crew to talk to. No indications at this stage."
It was difficult to say if the FV Jubilee was damaged or not, he said, as it was sitting in an upright position and divers could not see the underside of the vessel, or if there was any damage on the inside.
One area of interest was how the life raft came to be inflated on the surface of the ocean, Mr Burfoot said. In their distress signal, the crew had indicated they were preparing to get into the life raft.
"The life raft being on the surface doesn't really mean to say they got to the life raft because they're designed, when a boat like this sinks, to automatically release from the boat and inflate when they get to the surface.
"That's an area of interest of ours, of whether that did happen automatically or whether it was released manually. We should be able to tell that from the divers' footage."
Investigators would look at the release mechanism in order to determine that, he said.
A statement would be issued later this morning, a police spokeswoman said.
