Maritime New Zealand has introduced new safety guideline for adventure tourism operators.

It cover vessels involved in swimming operations, those offering high-speed / thrill-ride experiences, parasailing and shark cage diving operations.

Spokeswoman Sharyn Forsyth says the guidelines are in response to serious incidents and provides practical guidance on how to manage hazards.

She says people have been seriously injured by getting too close to propellers while swimming with dolphins.

Forsyth says it also covers operators offering experience of swimming with dolphins and those offering high-speed / thrill-ride experiences.

"Thrill rides and experiences often when you've got vessels moving across the water at high speed there's a danger of back injuries in particular," she says.

"So in these guidelines we set really clear expectations as to how to ensure that peoples backs are protected."