8 The critical evidence is as follows:
a The ship was berthed at Darling Harbour on 18 January 2000, and was in the process of discharging its cargo of vegetable oil, known as palm stearin. The ship was, according to the evidence of Ms J de Wit, the shipping manager of the Sydney Ports Corporation, carrying 399 tons of palm stearin as bulk cargo.
b At about 0815 hours on 19 January 2000, Mr L Barnes, a port officer employed by the Sydney Ports Corporation, made a routine inspection of the ship.
c On arriving at the berth, Mr Barnes saw small clumps of what looked like a vegetable oil product floating in the water between the starboard side of the ship and the wharf. He saw vegetable oil on the ship's side beneath and around the starboard aft scupper outlet. He went on board the vessel and went to the starboard aft main deck scupper. He saw that the scupper plug was not in the scupper and he saw vegetable oil around the scupper, the deck area and the base of the manifold drip tray on the main deck.
d Mr Barnes took samples of the vegetable oil from various parts of the ship and the water. Four of these samples were later analysed by Mr J F Leeder, an analytical chemist. His analysis demonstrated that the samples taken from the shell plating starboard side of the ship around the aft main deck scupper outlet, from the surface of the water, and from the main deck, all matched and were a vegetable oil known as palm stearin.
e Mr G Edgley, another officer in the employ of the Sydney Ports Corporation, arrived at the ship at about 0830 hours on 19 January 2000. He observed vegetable oil down the side of the ship's shell plating to the waterline, and there were small clumps of vegetable oil in the waters surrounding the ship. He estimated that there was between 40 and 50 litres of vegetable oil in the water. On board the ship, he saw vegetable oil on the main deck surrounding the main deck aft starboard scupper opening, and on the main deck beneath the starboard manifold drip tray. Mr Edgley observed that the manifold drip tray drain pipe plug was missing and the drain pipe from the drip tray was blocked with a rag.
f Both the crew of the ship and personnel from the Sydney Ports Corporation put in place a clean-up operation. Mr Edgley estimated that the clean-up was completed by approximately 1030 hours.
This evidence establishes beyond reasonable doubt that a discharge of palm stearin (carried as bulk cargo) occurred from the ship into the water of Darling Harbour on 19 January 2000.
9 The absence of an agreed statement of facts arises out of a report prepared on behalf of the defendants by a marine surveyor, Mr A M Kirkland. His opinion was that there was no evidence that a discharge had occurred, and that, if there had been a discharge, he could not precisely say how it occurred, although he was prepared to make a hypothesis about that aspect. However, the respective pleas of guilty amount to an admission that a discharge occurred from the ship into Darling Harbour.
10 There is no evidence to establish how the discharge occurred. Mr Edgley's opinion was that the vegetable oil escaped from the main deck through the main deck starboard aft scupper into the water. Mr Kirkland thought that, if a discharge had occurred, it would have been caused by the melting of previously solidified oil in the starboard aft scupper pipe brought about by the effect of the morning sun. Mr Kirkland's opinion was simply a hypothesis, and it is one upon which I place little weight. He did not arrive at the ship until about an hour and a half after the clean-up had been completed, and his opinions were cast in doubt by the evidence of both Mr Edgley and Mr Barnes, who were there when the vegetable oil was observable, and by a subsequent analysis carried out by Mr P E Burge, a consultant marine engineer, engaged on behalf of the prosecutor.
11 Ultimately, however, very little turns on the how the discharge occurred. It would have assisted the Court to know how it occurred so as to consider whether the circumstances of its discharge had any connection with the culpability of the defendants. But they have each pleaded guilty to the offences with which they are charged, they thereby admit the elements of the offence, and, in any event, the evidence establishes beyond reasonable doubt that a discharge of palm stearin occurred from the ship into the water at Darling Harbour.