THE Mooloolah River entrance remains a sand hazard for some vessels despite intermittent work by two dredges in the past two months.
A survey this week found the water depth about 100 metres north-west of the western break water could drop to 1.2m at the lowest tide. Last week, it was 0.7m.
A fishing boat ran aground on a sandbank on Sunday, while a trawler being towed into Mooloolaba with mechanical problems yesterday was forced to wait for hours until the afternoon high tide to attempt a crossing.
The survey shows a sandbank outside the river entrance and another larger bank to the south-west.
Paul Williams, who operates a trawler and a long-line boat, said he was surprised at the amount of sand still around the mouth despite the dredging.
He also could not understand why there were no leading lights operating to guide boats in during the dark.
"We don't know what's going on," he said.
Kristian Penny, seafood manager at the Mooloolaba Fish Market, said 65-70 foot fishing boats drew 2.5-3m of water and often had to wait for high tide to come into Mooloolaba.
Allan Harvey, skipper of the charter fishing boat Flatdog, said his boat with its 1m draft was not as troubled by the sand build-up as the larger vessels.
"My advice would be proceed with caution. It's not the best that I've ever seen it but it's not the worst," Mr Harvey said.
A Maritime Safety Queensland spokesman said sea conditions on the Sunshine Coast meant dredging and surveys had been postponed.
The spokesman said the weather conditions meant that the channel depths could not be confirmed and lead lights could not be reliable, so they had been turned off as per standard practice until a safe course could be confirmed.
The dredges would be back at work as soon as the weather allowed, he said.
Mr Penny said difficulties arose when larger boats had near-misses with paddlers and surfers.
He said paddlers and surfers often crossed the boats' paths.
"They don't seem to care. They're looking at the waves, not the boats coming through," he said. "It's an accident waiting to happen."
Mr Harvey agreed that the combination of boats dashing around sand banks and personal watercraft was a dangerous mix.
"That's the biggest problem. You come around the corner and you have to make a dash and then all of a sudden, there's some kid on a kayak paddling in front of you," he said.
BATTLING THE BAR
Mid-July: First dredge Saibai in place.
January 2: Fishing industry warns dredge can't keep up.
April 13: Bad weather delays arrival of heavy-duty second dredge Port Frederick.
April 15: Port Frederick starts work.
April 17: Port Frederick damaged when it runs aground.
May 19, 20: Port Frederick returns.