Space entrepreneurs Rocket Lab are appealing for boaties stay away when it again attempts to launch its test rocket this afternoon.

It was within a minute of lift-off on the Mahia Peninsula yesterday afternoon when two vessels entered the surrounding exclusion zone.

One was commercial, the other was private.

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The private boat was pursued by police, who are dealing with its crew, while the commercial vessel has yet to be dealt with.

By the time the intruders were moved on, the weather conditions prevented another launch attempt.

Rocket Lab CEO Peter Beck said the exclusion zone has been well-publicised for a week and a half with "signs on the boat ramp", broadcasts on the marine channel continuously, and ads in newspapers.

"It's pretty hard to miss," Beck said.

Beck is asking boaties who want to watch the launch to please do so via their livestream, rather than their boat.

The launch window opens again at 2.30pm this afternoon and Beck is optimistic.

"The weather is always a concern on these flights because we're looking for optimum conditions."

"But at the moment it's looking good for us to go for another attempt."