Water Safety New Zealand says four recreational drownings yesterday are concerning but not surprising.

A search resumed this morning for a man who was presumed to have drowned at a Northland beach yesterday afternoon. The bodies of three other men who drowned in the South Island yesterday have been recovered.

The Northland man, believed to be in his 20s, was swimming with about six others at Ngunguru Beach, about 24km from Whangarei, when he became separated from the group about 2.10pm.

Senior Sergeant Matt Rogers, of northern police communications, said it was likely the man was caught in a rip and carried out to sea past a sand spit.

A 45-year-old Invercargill man died in the Maroroa River, near the Mavora Lakes, after falling from his kayak at 1pm yesterday.

He was found a short distance downstream. An attempt to resuscitate him was unsuccessful.

About two hours earlier, a 51-year-old Korean man was swept to his death while fishing off rocks at Cape Saunders, a popular fishing spot on the Otago Peninsula.

A 22-year-old Brazilian national living in Ashburton drowned while swimming at Lake Hood.

Water Safety New Zealand general manager Matt Claridge said all of the victims were in the classic drowning demographic.

"They're all recreation based, which, given that it's a holiday weekend, is not surprising; however, it's still concerning."

Eighty per cent of drowning victims were male, with 66 per cent of male drowning victims aged between 15 and 54, according to Water Safety New Zealand statistics.

"It means for New Zealanders, regardless of time of year or the activity, that attention to basic water safety is important and, of course, ongoing," Mr Claridge said.

Only one person drowned during last year's Easter period.

On Saturday, before the end of daylight saving, the 2010 drowning toll stood at 30 -- eight less than the same time last year.