A big day on the water in Auckland has just got underway

Dragon boat racing on the Viaduct Harbour have marked the beginning of the 185th Auckland Anniversary Day Regatta -- New Zealand's oldest sporting event.

Racing is also underway for three of seven yacht clubs involved, racing in 29er, 420 and 470 classes.

Regatta chair Bill Lomas says also among the big visual events is the tugboat race.

He says about 17 tugboats will race from the Harbour Bridge to the Port and back from about 10am.

Winds are expected to be fresh for the sailors -- with southwesterlies hitting an average of around 20 knots.