Person rescued from the water off Mullet Bay, Motutapu Island

A person has been rescued from the water by the Coastguard after reports a vessel was on the rocks at Motutapu Island's Mullet Bay. Photo / Darren Masters

A person has been rescued from the water by the Coastguard near Mullet Bay, Motutapu Island just after midday today.

The Coastguard was alerted by a passing vessel via Channel 16 VHF that a vessel was on the rocks at the Motutapu Island bay.

"Coastguard broadcast a distress relay on our channels to which both Howick and North Shore units responded," a Coastguard spokesman said.

North Shore Rescue, which was already at Matiatia on the neighbouring Waiheke Island, responded within five minutes and rescued a person from the water.

"Volunteers assessed the person on board and transferred them back to Matiatia," the spokesman said.

Coastguard Duty Officer Tony Winyard: "Coastguard North Shore responded very quickly to the incident and work efficiently to rescue the individual, particularly given the proximity to the rocks and high tide conditions."

Earlier today, New Zealanders were urged to be cautious while out on the water.

This follows one of the deadliest summers for drowning in New Zealand in decades.

Maritime NZ's Matt Wood says it's important people prepare for all water conditions.