'Tis the season to be jolly - and go shark cage diving.
Today marks the beginning of shark cage diving season which runs from December to June.
A recent international review by a world shark cage diving expert has found no evidence cage diving increases the risk to swimmers.
Department of Conservation (DOC) operations director for the southern South Island Allan Munn says the review gives DOC the best available information for guidance.
DOC is keeping a watchful eye on the two cage diving operators in Stewart Island this season.
They announced they will tighten permit conditions and increase monitoring of commercial operators to ensure cage diving activity is not harming sharks or causing increased risk to people.
Both operators are on their last warning DOC says, after one company breached conditions last season over bait use. Their permits will be revoked if conditions are breached again this season.
A number of changes have been made to the operating permits after being introduced in 2014.
Changes include more control over bait and berley (ground fish) use and limiting operators to using one vessel a day. Operators can only cage dive on one site 8km from Stewart Island and are prevented from feeding sharks around people.
Great white sharks are a protected species and about 100 visit Foveaux Strait between December and June each year.
The permits will be reviewed again in August next year.