AREA TO BE AVOIDED. To avoid risk of pollution all vessels greater than 500 gross register tonnage or 40 metres length overall shall avoid the area of this chart. Exemptions apply to: a. All vessels of the Royal New Zealand Navy. b. Vessels having obtained permission from the Chatham Islands Harbourmaster to visit a port in the Chatham Islands. See New Zealand Annual Notices to Mariners 10 for details.