Frigate scuttled off NSW coast after dolphin delay

Smoke rises from pyrotechnics during the scuttling of the HMAS Adelaide off Avoca Beach on the NSW Central Coast north of Sydney. Photo / AAP

The planned scuttling of a former Royal Australian navy ship off a New South Wales beach has already faced a multitude of delays - and today, there was another last-minute hitch.

A crowd of 50,000 people turned out off Avoca Beach to see the sinking of the HMAS Adelaide, which is expected to become a popular dive site.

Almost every hotel and motel in the area have been booked out by excited spectators.

The planned sinking was to happen at 12.30pm (NZT) - but a pod of dolphins decided to frolic inside the exclusion zone and close to the ship, granting the doomed frigate another hour or so of existence above the surface.

Controlled explosions were finally detonated on the decommissioned frigate at 1.50pm (NZT), sending it to the bottom of the ocean.

It took less than a minute for the vessel to sink.

The scuttling was initially delayed about a year ago after the No Ship Action Group claimed PCBs (polychlorinated biphenyls) and toxic substances were leaking from the former navy frigate.

The action group and the Environmental Defender's Office won a legal victory which overturned a permit allowing the ship to be sunk.

For a year the retired vessel remained stationed at Glebe Island.

The Administrative Appeals Tribunal eventually gave the scuttling the green light to proceed, after the absence of any harmful toxins was proved.

That decision culminated in today's hghly-watched event.

The Ex-HMAS Adelaide Artificial Reef Project is an initiative to create an internationally acclaimed dive site on the NSW Central Coast.

- NZHERALD STAFF, AGENCIES