The area's coastline is now home to an artificial reef weighing 90 tonnes after its pinnacle towers were installed off the coast after years of preparation.

Minister for Agriculture Adam Marshall said the area would have anglers trying their luck.

"It's designed to support a large variety of fish species - especially bottom-dwelling and pelagic species that are popular with recreational fishers," he said.

"Although the fish community will rapidly evolve and change in the next few years, patience is the key as the reef will only improve with age."

The towers were floated, towed and sunk remotely from a nearby tugboat to avoid the use of barges and cranes in open ocean.

It is designed to remain intact about 3.5 kilometres off Swansea Bar in 28 metres of water for decades.

"This is by far the safest method for installation and has been adopted from the oil and gas industry and the methodology for installing oil rig platform 'jackets'," Mr Marshall said.

Previous offshore reefs in NSW have attracted species including yellowtail kingfish, bonito and blue mackerel.

"This design deflects currents and creates upwellings, while also providing shelter for fish among the large base structure with its various shapes and crevasses," Mr Marshall said.

"The steel structure is the skeleton of the new thriving fish community; but the ocean will ultimately do the rest with the reef rapidly accumulating a wide variety of attaching marine organisms."

The reef was funded through the Recreational Fishing Trust.