Well spotted tinman. So for those who are interested, this is the definition of customary title as stated in the act. Customary marine title exists in a particular part of the common marine and coastal area if the applicant group— (a) holds the specified area in accordance with tikanga; and (b) has exclusively used and occupied the specified area from 1840 to the present day without substantial interruption.
The key will be what is exclusive use and substantial interuption. Only the Attorney General seems to know this but I suspect you will all be in for a nasty surprise soon. I truly hope I am wrong but like I said enjoy it while it lasts. And don't say you weren't warned.