"Usually, people will move off when noticed, so I thought maybe they have not noticed so I jumped into the tender, fired up the motor and as I did, they took off.
"They were not at anchor, they had the motor running and were drifting.
"We moved to take our customers along the coast to the wreck of the HMNZS Waikato and as we came around the Pinnacles here they were on the other side and fishing again.
"Kevin altered course towards them and they took off again."
Mr Ericksen said that in his eight years of visiting the islands on multi-day trips he had seen a few people apparently fishing 800m off the reserve boundary. But this time, he estimated the boat was in a channel "well within the reserve" about 50m to 80m off the High Peaks rocks.
"Our thoughts are that the marine reserves work only if everybody respects them. If the system breaks down it's not fair on everybody else."
DoC Northland spokeswoman Marie Jordan said the two men who were on the vessel spotted were Auckland residents on holiday.
Their statements were taken yesterday and a decision would be made on what further action should be taken. Whether any charges would be laid would be up to her managers.
Ms Jordan said all boaties took an interest in monitoring what went on in the marine reserve.
"This was pretty blatant behaviour. It definitely shocked us," she said.
She praised the charter vessel's crew for their vigilance.
- Additional reporting Northern Advocate