The Government's aviation watchdog has raised its eyebrows at the approach taken by Air New Zealand in a recent safety video.

The airline has won plaudits for its wacky videos, which often feature sports and movie stars and are elaborately produced - but the praise hasn't been universal.

In an email obtained under the Official Information Act, the Civil Aviation Authority critiques the airline's surfing video that came out last May.

The four-minute-forty-second film is set at the beach and features some of the world's top surfers.

The Civil Aviation Authority deemed the video acceptable for use, but not without reservations.

"As we have commented previously, the video diverges materially from the 'safety message' at times, and whilst I appreciate the need to engage the viewers, the extraneous material detracts from the scope and direction of the safety message."

The email refers the airline to a draft copy of the Authority's advisory circular on cabin briefings, advising it could be of assistance in producing future videos.

However, those have both been longer than the surfing video in question, with the current pre-flight video, featuring comedian Rhys Darby, clocking in at more than five minutes.

The airline would not be interviewed for the story but in a statement it said the videos were consumer tested with a cross section of customers prior to release.

It also told Seven Sharp last month that the videos engaged the attention of viewers.

"We took what was an instructional help video and turned it on its head and created really entertaining content that not only demonstrated the safety messages, and we saw more customers watching them as a result of it, but also a really amazing piece of marketable material," said Head of Global Brand Jodi Williams.

A marketing lecturer at the University of Auckland, Mike Lee, says the videos have been successful in enhancing the brand of Air New Zealand.

However the airline walked a fine line in creating videos that met their remit.

"They have to strike a balance between capturing people's attention and engaging the audience.

"And on the other hand, if you're too far out of the context you'll get the regulatory body coming in and saying it's a little too removed, people might not understand what you're trying to say."