The national drowning toll is now 110 - well above the five-year average of 94 per year.
Water Safety New Zealand says five of the eight drownings in November were men over the age of 55.
Chief executive Matt Claridge says people in the older age bracket should know better than to undertake water activity when alone or intoxicated.
Two men drowned while on their own, while a third case involved alcohol.
Mr Claridge says the death toll is too high and people are not taking responsibility for their own safety.
The most recent death was that of a diver at Kapiti Island on Saturday.
