The parents of a navy sailor killed when an inflatable boat flipped and trapped him underwater say his death was foreseeable and the result of incompetence.

Bill Solomon and Jayne Carkeek told an inquest into the death of their son, Able Seaman Byron Solomon, 22, following an incident aboard the navy ship HMNZS Canterbury, that safety risks which contributed to his death had happened before.

They also said the navy, and then-Defence Minister Phil Goff, should take responsibility for not inspecting the Canterbury thoroughly enough for safety before it was launched.

AB Solomon, 22, drowned when the inflatable boat capsized as it was being launched from Canterbury during a training exercise northeast of Cape Reinga on October 5, 2007.

A navy inquiry found a hook used to attach a rope from the inflatable to the ship was faulty and similar hooks were replaced throughout the navy.

Mr Solomon and Ms Carkeek both made statements about his death before Coroner Brandt Shortland today.

They both said that there had been similar rope failures before, aboard the HMNZS Wellington in 1998.

However, they said that not only had insufficient attention been paid to rectifying the problem, it had not even been formally identified as a hazard.

Mr Solomon said that despite evidence presented yesterday which said there was a standard operating procedure (SOP) into how to deal with boat rope releases, a navy court of inquiry had found there was no specific SOP into an inflatable boat broach alongside and the subsequent trapping of personnel.

"Despite there having been numerous instances of a boat rope failure, one as recent as the previous day, no one formally identified such a failure or hazard," he said.

"As a result there was no SOP, only an assumed solution which the court of inquiry recognises as insufficient to avoid disaster."Mr Solomon said developing a strategy which either eliminates a hazard or reduces the risk would have been expected of a reasonable employer.

"It would seem that the employer places more emphasis on the polishing of buttons and boots than it does on the genuine safety of its people," he said.

"It is my contention that our son died as a result of incompetence."

Mr Solomon also said the Government-commissioned Coles Report had said the programme to commission the HMNZS Canterbury "has been managed to get the ship into service as soon as possible, and it has been characterised by shortcomings in project management and governance and collective wishful thinking".

He said there were expert witnesses who said the issue would have been identified and rectified if more time had been devoted to it.

"It is my belief that shortcuts were taken and that these shortcuts were sanctioned from the top. The buck must stop somewhere and in this case it stops with the Minister of Defence of the day, Phil Goff," Mr Solomon said.

"The Coles Report also says senior members of the navy were keen to see Canterbury launch so that morale could be maintained and that the flow of personnel leaving the navy would not turn to a flood."

Ms Carkeek said that her son's death was "foreseeable and preventable" and that he had expressed some concern about his transfer to Canterbury shortly beforehand.

"It's ironic that a man of Byron's limited experience was able to identify the risk that was to take his life."

Mr Shortland reserved his decision. He called for submissions to be made by February 19, and said that an interim report which would include "some adverse comment" would be released not too long after that.

He said the inquest was only focused on the immediate events surrounding AB Solomon's death and not wider project issues, though for some things it was "very hard to draw a line in the sand as to where to stop".