Boaties need to take responsibility to prevent more deaths at sea and remember what they are risking, a water safety expert says.

A man's fatal decision to go swimming after drinking at a party has his family urging others not to make the same mistake.

The national drowning toll for the first two months of the year rose to 35, after 15 drownings in February.

Six preschoolers have drowned so far this year - equalling the total for 2010 - and water safety campaigners say it is a shocking start to the year.

The drowning death toll will rise if school swimming lessons aren't made compulsory, the Government has been warned.