Big seas, whipped up by 40 knot winds have forced the Mackay Port Authority to close the southern break wall at the Mackay Marina.

Waves pound the break wall during high winds yesterday.

Communications manager Colin Wilson said the MPA took the responsible position to close the break wall to traffic and pedestrians, after huge waves lifted large rocks onto the roadway on Tuesday.

“At this stage it will remain closed until at least weekend,” he said.

“In the past, the action of the sea and gale force winds have lifted boulders from the seabed and sent them crashing onto the road.

“It’s just too dangerous for motorists and the public. A vehicle could be damaged or a fisherman could be swept off the wall by the wind and huge waves.”

Mr Wilson said the MPA was closely monitoring a deepening low in the Coral Sea and another low pressure system south-east of Mackay.