DANGEROUS marine activity on the region's lakes has prompted a warning from authorities ahead of Australia Day, when large crowds are again expected.
During the holiday period more than 200 vessels were intercepted and 72 marine notices were issued on southeast Queensland lakes.
More than 250 random-breath-tests were carried out with only one recording a reading above the legal limit.
Queensland Police and Seqwater rangers reported an improvement in the number of people wearing lifejackets while aboard vessels.
But they say there was an increase in the number of people caught operating high-power craft without appropriate licences, an increase in the number of people ignoring speed and distance rules and several registration offences.
During the Christmas period about 100,000 visitors attended recreational lakes and parks across southeast Queensland.
The findings prompted a warning from Acting Natural Resources, Mines and Energy Minister Mark Ryan for boaties to "act safely and responsibly''.
"With these large crowds, it's important that all members of the public take care and are considerate of fellow visitors,” Mr Ryan said.
"Even though the stillness of lakes can create a tranquil and safe feeling, still water can still be dangerous and accidents can happen if visitors get complacent.''
Mr Ryan said the rise in the number of people caught operating jet skis without a licence was disappointing.
"Some of those found riding jet skis without a licence were as young as 11 years old,” he said.
"If a jet ski is being operated by a young, inexperienced rider, there is a good chance it can result in a serious accident, especially in a crowded lake.”
With large crowds set to return for the Australia Day long weekend lake users are being urged to not become complacent about lifejackets.
Mr Ryan said people should take a moment before leaving home to check the latest recreation and safety notices and the Bureau of Meteorology weather forecast.
For information about Seqwater lakes visit www.seqwater.com.au.