They had already seen a fin piercing through the surface of the water only 10 minutes beforehand but the group of commercial divers were still preparing to jump into the mouth of Newcastle Harbour for another day's work.And then they saw it.
A huge shark, possibly a great white as long as four metres and estimated to weigh over 1000 kilograms, glided up to their boat near the southern breakwall, had a quick glance at them and swam directly underneath.
The sighting, on Tuesday morning, caused the closure of Nobbys and Stockton beaches in Newcastle before a further sighting of another shark near the Cowrie Hole prompted lifeguards to put up the red flags at Newcastle Beach.
Experienced commercial diver Dustin Besse, 31, was busy freeing up storage on his mobile phone when he caught the moment the shark cruised under their boat, which is three metres wide.
The shark's tail, more than a metre high, remained on one side of the boat while its head poked out underneath the other.
Fellow diver Adrian Blundell was suited up and only seconds from jumping in to work on a navigation marker when the predator made its appearance.
"He didn't jump in then and we took the kit off and we just kind of stood by," Mr Besse said.
"We saw it again and didn't see it and we waited about two hours and I ended up going in and finished the job off."
The job took 35 minutes, in about 20 metres of water and with little visibility.
But for the men, who work for commercial diving company Harbourworks, it was just another day on the tools.
"It was straightforward," Mr Besse said. "I do a lot of surfing, I know [sharks] are out there.
"It is not as if they are just there today, they are always there.
"We do a lot of work in the harbour where there is zero visibility - if you can see your hand, it is a very good day."
Newcastle divers video shark under boat as they prepare to enter water
