Two people were plucked to safety from a sinking boat moments after their desperate call for help was cut off.

The Coastguard said the pair's 4.4m runabout started sinking near Kawakawa Bay, north of Maraetai, east Auckland, this evening.

"The two people on board made an emergency 111 call which was cut off as their vessel sank, but they were plucked from the water by a passing vessel while a police helicopter kept watch overhead," Coastguard said.

Coastguard Maraetai volunteers had just come back in from training and another incident.

They responded quickly to offer assistance, ferrying the boaties back to shore.

Both people aboard were wearing life jackets.