There are three types of rules to be aware of:
Most regions have rules about biofouling and/or marine pests. These are slightly different between regions, but generally, if your hull has no more than a light slime layer, you’ll be good to go.
Some marinas take extra steps to protect themselves including the ‘6 or 1’ rule. To visit these marinas you may need to provide evidence of either an antifoul within the previous six months, or a lift-and-wash within one month of leaving an area infected with marine pests. Ask for more info when you make your marina booking.
There are also restrictions related to exotic caulerpa species including locations where you cannot anchor or disturb the seafloor.
These rules are designed to protect our coastlines from marine pests which can have devastating impacts on the places we love visiting.
This summer divers will be checking boat hulls in locations across the regions such as the Bay of Islands and Bay of Plenty, and hull surveillance can take place at any time of the year throughout marinas in Northland, Auckland, Waikato and the Bay of Plenty in the north.
In the Waikato region for example, over 900 vessel hulls, 15km of pontoons, 1,263 piles and 724 hectares of area were surveyed for marine pests in the last year through the Coromandel Peninsula.
Yes, a clean hull is important but the notion that not anchoring where Caulerpa exists will stop the spread is nonsense. Marine fauna, tides and currents will do that quite well.
The fact is, with overseas vessels visiting continuously we will get introduced pest species.
Interestingly, on my marina, when fanworm caused a major panic some years ago, you could see them spreading rapidly. Today they are still there but much rarer. Most species tend to explode in a new environment and then reduce to a balance.
Many indigenous species here originated in South Africa or South America!