Newcastle Harbour in New South Wales is one of the busiest coal ports in the world, with large ships cruising in and out of the waterway around the clock.
A crew of 22 marine pilots play an integral role in seeing that ships visiting the port enter and exit safely.
It is their job to fly offshore to the next ship waiting to enter the Port of Newcastle.
They board the vessel and provide the ship's master with a range of information about conditions in the port and details of where the ship will berth.
They then oversee the ship's approach to Nobbys Head and its careful cruise down the harbour.
A unique port where safety is a top priority
Phillip Hawke is one of 22 marine pilots who work at the Port of Newcastle, and has been in the job for eight years.
He was born and raised in Newcastle, and spent the early part of his career at sea.
"For vessels waiting off the port, they're under the command of the master on the vessel. They can call up and ask for advice ... but it's still the master's responsibility to make his determination," he said.
"If we determine that the entrance, or the conditions within the harbour are unsuitable for a vessel to enter, we would give them early advice that the vessel's not entering.
"Then they make the decision generally to go back out to sea, out to deep water, and wait for the next time that they would be advised that we are boarding."
Hunter River tide a factor in when ships can enter
Newcastle's port is unique, mainly due to its relatively shallow depth.
Being part of the Hunter River, the ebb and flow of the tide is a factor in when ships can and cannot make their passage.
"Because shipping is not regular — it often happens around the tides — we work an on-call roster," Mr Hawke said.
"We might need five pilots on the water, and other times during the day we may only need one pilot.
"The actual channel itself, under international standards, is designed for a Panamax-sized vessel, which is a vessel that's 225 metres long; but we're handling vessels up to 300 metres long here in that channel — that's to do with the width of the channel."
Mr Hawke said the depth in the channel was maintained at 15.2 metres.
"Most of the Panamax vessels would not load past that, so they can sail at any time of the tide," he said.
"But with our large Capesize vessels, they can load deeper, so they generally sail on the high water because they're trying to maximise their cargo.
"Some of those Capesize vessels will only load to around the 15-metre [level], or whatever the tide is allowing them to, and then go to their discharge ports.
"But other times they'll go north to some of the Queensland ports which have deeper draughts, and then they can load to 17 or 18 metres and continue on their voyage."
A careful process
The procedure of bringing ships in to the Port of Newcastle can take up to two-and-a-half hours.
About 45 minutes before entry, the marine pilot travels to Dyke Point on the shores of the harbour, where they board a helicopter.
The chopper flies three-and-a-half nautical miles south of the harbour entrance — approximately offshore of Merewether — to the designated boarding area.
"Once we're on board the ship, we give the master a brief rundown of the pilotage and what will be undertaken, which just includes local conditions, the number of tugs we'll be using, the berths we're going to, and basically an explanation of what we intend to do," Mr Hawke said.
"That gives them time to [ask] any questions [they] have. Many of the ships that come here are regular callers, so they're very familiar with the port; but then it's a time where they also involve the rest of their team on board on the bridge.
"Once everyone is happy, we make the approach to the entrance and undertake the pilotage."
The pilotage process takes about one hour, then another 30 minutes to moor the vessel.
"On an average day it does fluctuate, but probably a standard day is around 15 to 20 movements per day," Mr Hawke said.
"Every port has challenges in the vessels they're handling.
"The weather here, particularly on the east coast of Australia, can change quite quickly. Weather is always challenging.
"Some days the weather is nice and very enjoyable; other days you're working at three o'clock in the morning and it's rainy and windy and it's not very enjoyable; but every job is different and it's satisfying in that regard.
"It's a very rewarding job; it's a fairly unique job. It's not a job that everyone would enjoy, but it's certainly very rewarding."
Source: ABC News