The Government's Covid-19 website states: ''You can go outside for a walk, but you need to avoid contact with others. Stay 2 metres away from others.''
It also says people can use their own transport only to access essential services.
In her daily press conferences Prime Minister Jacinda Ardern has said people shouldn't drive to the park or beach to exercise but should stay in their ''local area''.
The Tauranga Bay woman said Ardern had defined ''local area'' as anything within walking distance. That worked in the cities but in a rural area such as Whangaroa, people considered a beach 30km away part of their local area.
''This is what they consider their local beach so cars are coming and going all day. We're going to end up with a cluster [of Covid-19 cases] up here simply because people are not listening. They just don't get it. Northlanders are so laid back they think it won't happen to them.''
The woman said she had contacted Mayor John Carter and Northland's top cop, Superintendent Tony Hill, for clarity on the lockdown rules.
She had also asked the council to put up a sign at the start of Tauranga Bay Rd barring non-residents, but had been told only police or Civil Defence could do that during a state of emergency.
Similar concerns have been raised by residents at Coopers Beach, Taipa, Mangonui's Mill Bay, and Hokianga Harbour, in the Far North and across other parts of coastal Northland.
Coastguard New Zealand has asked boaties not to head on to the water because if anyone needed rescuing Coastguard volunteers would have to break self-isolation to help.
Shore fishing, however, is permitted, as long as fishers follow social distancing rules and don't interact with people outside their self-isolation ''bubble''.
On Wednesday, just before the lockdown began, Police Commissioner Mike Bush said:
''You only go out in your vehicle if you need to go and get essential food supplies, essential medical supplies or medical treatment. Otherwise, please stay at home.''
Yesterday, however, Civil Defence emergency management director Sarah Stuart-Black said people were permitted to drive a short distance to get exercise. Cycling and swimming were acceptable but Civil Defence did not want dozens of families turning up at the same beach and ignoring social distancing rules.
Ultimately people needed to use their common sense.
• Covid19.govt.nz: The Government's official Covid-19 advisory website
