Interislander has provided passengers with tips to avoid seasickness for the other sailings.
A lingering low-pressure system is bringing rain or showers to many parts ofNew Zealand, with thunderstorms, large swells and strong winds affecting the centre of the country.
Interislander posted a service alert on its website, notifying passengers the 6.15am Picton-to-Wellington crossing on Friday had been cancelled because of the rough sea, as had the 11am return service.
MetService said people could expect 150-200mm of rain there, on top of what had already fallen, especially about the Wairoa ranges. Peak rates would be 10-20mm/h.
Strong wind watches remain in force for the following areas:
Kāpiti Coast, Wellington and coastal Marlborough including the Sounds; to 4pm on Friday.
Taranaki and western parts of Whanganui; to 4pm on Friday.
Coastal areas of Hawke’s Bay and Gisborne/Tairawhiti; to 6am on Saturday.
MetService warned southerly and southwest winds may approach severe gales in exposed places.
In a post on social media, it said large, powerful 4m southerly swells were impacting the south and east coasts of the North Island.
A heavy swell warning was in place for Wairarapa (Turakirae Head to Mataikona) until 8am on Saturday.