Crowds of people, including four lucky year-12 students from Batemans Bay High School, packed the southern side of the Clyde River to watch the barge cross under the bridge at 1.15pm.

Mr Archer said the second barge would allow more efficient construction on the new bridge.

"The second barge gives us extra capacity to assist the first barge," he said. "It allows two lots of piling rigs to work at the same time.

"The best way to reduce the time of the project is to have more options available, so if you get two lots of equipment in, it helps keep the program running."

Mr Archer said the new barge would assist in setting the foundation of the bridge through a process called marine piling.

"The piles are the foundations of the bridge that hold it up off the river bed," he said. "What the piling rigs are doing is putting steel tubes down into the river bed.

"They get vibrated through the sand and mud down to the rock, and all the sand and mud is excavated out.

"We bore into the rock with a socket that's four or five metres deep, and that gets filled with concrete.

"The rest of the bridge that sits on those piles won't get washed away in a big flood. It's sitting on bedrock.

"They're taking approximately a week to bore each pole into the river bed, and they're also making concrete shells that will be placed on top of the piles.

"We call them pile caps, and the piers will be built off that.

"I'd imagine it'll be at least a month or so before we start seeing the piers coming out of the river."

The four year-12 students had a front-row seat, and were taken on a tour of the construction site after the barge crossing to commemorate Monday's International Youth Day.

Chelsea Yakaunak, Stella Cross, Finn Jeffrey, and Elijah Kinnane met with members of the John Holland team, and had the chance to talk to Mr Archer and project director Justin McCarthy.

Bega MP and Minister for Transport, Andrew Constance, said the theme of International Youth Day was 'transforming education'.

"International Youth Day is a day to raise awareness of the positive role young women and men play in our community, and to celebrate it, we wanted to share with students an up-close look at the project and this historic milestone," he said.

"We're committed to providing young people life-changing learning opportunities through this project.

"The project team will work closely with local schools to provide work experience opportunities to give students a taste of the various disciplines required to build this bridge, including engineering, environment, design, safety, and community engagement.

"We also want to remind the region's young people that recruitment for Transport for New South Wales' 2020 Apprentices and Trainees is open, with 10 positions available in the Illawarra, South Coast, and Monaro regions."