Half of New Zealand drownings happened when people were least expecting to get wet, according to the latest Water Safety NZ (WSNZ) statistics.

"There is a misguided preconception that people drown while swimming, but typically over half the drownings are when victims had no intention of recreational activity," WSNZ project manager, Matthew Claridge said yesterday.

Sixty-one people have drowned in the year to June - one fewer than in the same six-month period last year.

Fifteen died accidentally after falling or slipping into water, 11 in motor vehicles and nine in recreational boating activities.

Most of those drowned were males (40 deaths).

The age group with the most drownings was 15-24 (16 deaths).

Inland waterways - rivers, streams and creeks - claimed more lives (21 deaths) than other locations.

Mr Claridge said accidental drownings reflected a group who were moving beyond parental supervision and who had a tendency towards risky behaviour.

"They're going to the river with their friends and slip or fall," he said.

Included in "accidental immersions" were three pre-schoolers who drowned in home pools. There was only one pre-school death in a home pool last year.

This year's toll of toddler drownings was "of concern that's for sure", Mr Claridge said.

Pre-schoolers could wander into an unsupervised pool area without parents or carers noticing, he said.

New Zealand has the highest number of drownings of children aged five and under among OECD (Organisation for Economic Co-operation and Development) countries.

Mr Claridge said that was why WSNZ encouraged changes to pool safety legislation.

"The risk to children has been identified as possibly increasing ," he said. "You could summarise the current [legislation as] being highly confusing, extremely inconsistent and hasn't evolved along with architectural and human evolution - it's no longer up to date."

The Fencing and Swimming Pool Act 1987 has never been amended and WSNZ is developing a pool fencing standard - a tool local councils can adopt outlining pool construction and safety standards.

"The Fencing and Swimming Pool Act is still the legislative requirement, but we are completing research that justifies a need for change, and the standard backed up by that research provides a credible alternative to the Act," Mr Claridge said.

One hundred and fourteen people drowned last year - the lowest since records began in 1980. The highest number of deaths was 214 in 1985.