Olympians Danyon Loader and Moss Burmester have joined hundreds of swimmers taking part in the annual crossing of Auckland's Waitemata Harbour.
About 1300 people will tackle the 2.8km course, swimming from Bayswater to the Viaduct Harbour from 10am on Saturday.
Race director Scott Rice says the event has attracted a broad range of competitors, making the field one of the strongest in the event's history.
Marine traffic has been stopped and Waitemata Harbour will be reopen to boats from 12.30pm.
