A man and his 7-year-old son are missing after their dinghy capsized in the Manukau Harbour near the old Mangere Bridge.

A Mangere man, 45, and his 7-year-old son had been missing since their aluminium dinghy tipped over under the old Mangere Bridge, sending a group of five into the water. Rescuers pulled three children to safety.

Witnesses say children tipped into a powerful current when their family's dinghy capsized this afternoon were desperately calling for help as they clung on for dear life.

Stability limitations with the Easy Rider are shared by other boats of the same design, according to the Transport Accident Investigation Commission.

This week marks the 100th anniversary of the most famous shipwreck. But, Greg Dixon asks, should we care?