Big boats are hitting our shores, and they're putting millions of dollars into the local economy.

Between April last year and March this year 57 super yachts visited New Zealand, 20 more than last year.

Marine Industry Executive Director Peter Busfield says the tourism and marine industry spend is huge.

"It varies from yacht to yacht, but on average we believe that a visiting super yacht will provide $4 million on expenditure in New Zealand," he said.