Water Police alongside Victorian Fisheries Authority (VFA) officers took to the Goulburn River to encourage safe boating over the long weekend.
Operation Spiny Crayfish ran from Friday 5 to Sunday 7 June and saw police and VFA officers conduct over 70 checks of vessels across the Goulburn Valley waterways in Toolamba, Nagambie and Kotupna.
Breath testing was conducted on board several boats and five operators under the age of 21 were found to have a BAC over 0.00 per cent, the legal limit for boat operators under 21-years-old.
A further two operators, a 52-year-old Gisborne and 43-year-old South Morang man, were found to be over 0.05.
They blew 0.107 and 0.078 respectively and received fines over $800.
A further eleven penalty notices were issued for life jacket offences and incorrect use of navigation lights.
Water Police Senior Sergeant Paul Gatty reminded Victorians that drink driving, and reckless behaviour, can have tragic consequences for those undertaking activities on the water.
"Each year we see near drownings, capsized boats, broken-down vessels, poor personal watercraft (PWC) behaviour and, sadly, fatalities.
"We encourage locals and visitors alike to enjoy Victoria's beaches and waterways but remind everyone to be responsible in and around water.
"While summer sees higher numbers of people take to the water, safety is something that needs to be considered all year round.
"If you're operating a personal watercraft or boat, make yourself familiar with waterway rules.
"Blood alcohol limits apply for recreational boaters. Those under the age of 21 must have a BAC of 0.00 per cent, while those aged 21 years and over must not exceed a BAC of 0.05 per cent," S/Sgt Gatty said.
Victoria Police encourages anyone operating a personal watercraft or boat to undertake the appropriate safety and equipment checks, and always familiarise themselves with the waterways rules before getting underway.