An investigator from Maritime NZ found the management of the boat, the GOM 379, wasn't complying with industry best practice because the rope wound around a winch drum was coiled, not flaked, which would have allowed it to be easily pulled.
"This failure has been a contributor to the circumstances of the death. A further contributor to the death is the absence of a dedicated winch operator," Corner Crerar said.
If such a person was there, they could have immediately stopped the winch control and reversed if necessary, limiting the severity of Triyono's injuries, the Maritime NZ report found.
Maritime NZ wrote to GOM 379's owner advising of best practice in the area and to immediately change the way it operated the winching.
Coroner Crerar recommended Maritime NZ "continue with its supervision of fishing boats owned and operated by companies based out of New Zealand".
"I am advised that MNZ is preparing a safety bulletin for the fishing industry containing advice on the basic safety guidelines that should be followed when operating winches.
"I recommend that these guidelines be developed and enhanced."
GOM 379 sailed from Bluff on April 12 last year, with a crew of Koreans and Indonesians aboard.