Worksafe New Zealand is warning it will crack down immediately on adventure tourism companies that operate without safety audits.
Under a new safety regime, 348 adventure activity operators had to be registered by Worksafe New Zealand by today, but just 86 met the deadline.
Another 199 have until December but a number of companies will be operating illegally if they open their doors tomorrow.
Worksafe chief executive Gordon MacDonald said an enforcement campaign would start tomorrow and illegal operators faced fines and court action.
"We've got 20 trained inspectors who are going out from the first of November checking on those who might be offering adventure activities illegally and will be taking action where we come across those circumstances."
Water or air-based activities are excluded because they have their own regulations.