Nappies wash up after NSW ship loses cargo

Nappies and surgical masks are washing up on NSW beaches after a vessel lost dozens of shipping containers overboard in rough seas off Newcastle.

Boaters have been warned to watch out for potential hazards with 83 containers coming loose and a further 30 badly damaged on the Liberian-registered ship.

The YM Efficiency was making its way from Taiwan to Sydney on Thursday night when it encountered heavy swell which should prevent it from docking there until Sunday.

Roads and Maritime Services said two containers were spotted about 100 metres off Fingal Head and Boondelbah Island, near Port Stephens, while sections of another container were found on rocks at Yacaaba Headland.

A helicopter scoured the coastline on Saturday for the 40-foot containers while nappies, surgical masks and plastic containers are among the first debris to wash up on Jimmys Beach and Rocky Point.

The ship was operated by the Yang Ming Marine Transport Corporation and a spokeswoman said there were no dangerous goods or contaminants inside.

"There is no security concern about the condition of the vessel," she said in a statement to AAP.