Severe weather has forced changes to the Majestic Princess' New Zealand itinerary resulting in two of its scheduled port calls in New Zealand being cancelled.

The change is painful for Princess Cruises and the guests onboard, especially those on the five-night seacation cruise from Sydney, as they will now have no port calls during their voyage.

In a letter to passengers, Captain Tony Draper says high winds and heavy seas around the North Island meant the ship could not stop at the Bay of Islands on Friday and Tauranga on Saturday.

'We realize the cancellation of a port of call, regardless of the reason, is disappointing. When we create itineraries, we look forward to taking our guests to the destinations they expect to visit. When unexpected issues occur, and we must make the decision to change our itinerary, we share in your disappointment," says Captain Draper in his letter.

'We will now sail directly to Auckland... where we will anchor outside the port to avoid the worst of the weather system.

'While we may still experience some rough seas, this should enable us to avoid the worst of the weather and provide you with the most comfortable cruise.”

The ship was anchored off the coast of Auckland's Browns Bay on Saturday night and is due to arrive at the Ports of Auckland this morning, Sunday April 9.

A Majestic Princess cruise ship passenger has been taken to hospital by helicopter after suffering a medical event.

The elderly woman was evacuated from the Majestic Princess cruise ship and taken to Auckland City Hospital in a serious condition about 8.15am on Saturday, an Auckland Rescue Helicopter Trust spokesperson says.