The captain of a luxury Sydney party cruise on which a woman died has been convicted for failing to pick up boat defects that did not directly contribute to her death.
Paul Arthur Titze had pleaded guilty to unreasonably placing others' safety at risk after an investigation found a number of deficiencies on board catamaran Lady Rose that were not detected.
Shalina Abdulhussein, 39, was found unconscious in the bathroom during a birthday trip around Sydney Harbour on February 2, 2019.
A coronial investigation into her death is still under way but a report found she likely died from the poisonous gas hydrogen sulphide.
On Monday magistrate Greg Elks fined the skipper $2000 saying his failure to notice life rafts were tied up and unable to float free was a serious breach and should have been picked up during his pre-start checklist.
But he accepted Titze's defence that he could not have been expected to know or see the problems with the plumbing and sewage tanks.
Other defects later found on the Lady Rose included missing insulation in the engine room and a "grizzly" and "cheap shot" repair job to the piping system.
The master and engineer said he had noticed the sewage tank levels were unusually high before departing on the fatal harbour cruise but thought he could manage the levels on the 27-person charter.
The investigation later found a hole in a jammed open valve meant harmful gases could float up from the sewage tanks below the boat decks while a hose used to ventilate the tanks was blocked by water.
"Creating an environment in which the gas could flow in the unfortunate sequence of events through the hole in the blocked valve in the base of the toilet cubicle in question", prosecutor David Staehli SC told Downing Centre Local Court
The circumstances with the "unfortunate disastrous result"' were rare, the court heard.
Titze's lawyer Edward Cox SC argued a half-hour allotment to conduct all checks was not sufficient time for such detailed inspections required to pick up on those defects that a specialist took days to find.
In giving evidence Titze also said a number of checks were not part of his mandatory schedule and was the maintenance department's responsibility.
But Mr Staehli said a passer-by would have seen the lifeboats were incorrectly tied up.
Throughout the evening in question guests made several complaints of bad smells permeating the vessel which Titze said was not uncommon.
Despite shutting off one section of the toilets the complaints persisted and he secured the boat at a suitable marina to pump out the sewage.
Ms Abdulhussein was found in a cubicle soon after but was unable to be revived.
The Australian Maritime Safety Authority had laid other charges against the now 45-year-old skipper but these have since been withdrawn.
He had been working with All Occasion Cruises for 13 years and regularly teaches relevant courses at TAFE.
Mr Elks found Titze to be a truthful witness who takes his responsibilities as a captain seriously.