AS SHARK nets are dragged in ahead of wild weather, Coast beachgoers and ocean users have been warned to take caution around the water.

Surf Life Saving Queensland Sunshine Coast regional manager Aaron Purchase said about two-thirds of Coast beaches were closed yesterday because of perilous conditions and he expected that figure to climb today and tomorrow.

"I imagine most beaches would be closed tomorrow (Thursday)," Mr Purchase said.

"We're expecting to see some erosion and very large king tides.

"With the conditions expected we don't want people out there."

Maritime Safety Queensland yesterday issued a warning for boaties, especially recreational users, who might be best leaving their boats docked in the coming days.

MSQ general manager Patrick Quirk said boaties should have identified contingency plans and safe havens to ensure they can avoid serious damage or injury.

"It is vitally important to have identified sheltered areas or inlets and have options to move your boat if you are away during severe weather," Mr Quirk said.

"Secure your vessel with suitable lines, stow loose articles below deck, close hatches and reduce wind loading by removing furled sails, covers, bimini tops and any clears.

"Check your boat is watertight."

Meanwhile, Mr Purchase said the impending onslaught could have longer-term impacts on Coast beaches by altering the structure of current breaks.

"All the established banks are expected to shift and reform over the next few days," he said.

"The open stretches of beach will likely see the largest swells... but even Noosa and Mooloolaba will have some big swells."