More people are having to be rescued from the sea but there are fewer Coastguard volunteers available to help them, the Coastguard 2010 annual report says.
In the 12 months to the end of June, about 1000 more people were rescued compared with the previous year, in a total of 3722 incidents.
At the same time there was a drop of more than 10% in the number of volunteers.
Coastguard New Zealand chief executive Bruce Reid attributes that to the effects of the recession.
An upgrade of 38 of the organisation's 72 vessels has helped to improve response times, Mr Reid says.