The strike, which began on Monday morning and is set to last about three hours, is the Maritime Union's fifth in its pay row with Ports of Auckland.
Talks involving the Employment Relations Authority will begin on Tuesday aimed at breaking the impasse.
The 265 workers are seeking a pay rise of 4.9%.
The union says taking the strike action during the Labour Day weekend is a symbolic action intended to show that not everyone gets a public holiday.
Source:New Zealand News