It's the third cruise ship leaving from Sydney in the past two months that has had multiple reported cases of gastro affect passengers, and the second by the same operator Royal Caribbean.

Touted as a "floating stage", the Radiance of the Seas left Sydney Harbour on October 24, for an eight-day voyage on which opera, classical and musical theatre performances were scheduled to take place.

Australian performers Anthony Warlow, Jonathan Welch and Mark Vincent, and Broadway star Liz Callaway were all booked to perform.

A Canberra woman who fell ill on the cruise, and who does not want to be named in case it affects any claim from the cruise operator, said it looked to her as though it was not the ship's first outbreak.

She said sanitisation stations were set up quickly, and the buffet, to which passengers usually helped themselves, was instead staffed by waiters who handed out plates one by one.

The sanitisation stations were staffed by cruise employees who would squirt passengers' hands with disinfectant on the way in and out of public areas.

"They were so quick to get the sanitisation stations up and staff serving the food that way and they pulled staff from all over the ship, so it wasn't just the normal dining staff," she said.

Medical staff handed fact sheets to sick people, explaining what to eat and how to treat the illness.

She said some shows were cancelled after performers and staff also fell ill, although the cruise company denied any performances were cancelled.

A spokesman for Opera Australia, which had about five performers on the ship, said none of its performers reported falling ill.

The Canberra woman said she became sick on the cruise's last night, and that at one point she had to be taken to the medical centre in a wheelchair for a second round of medicine.

"What I had for lunch that day was obviously contaminated, because I took absolutely every precaution. In fact, a friend of mine on the cruise said, 'I can't believe how often you're doing your hands'," she said.

She also used paper towels to open bathroom doors, and avoided the pool and gym, which she said weren't closed after people became ill, although the kids' pool was.

She and other sick passengers were quarantined to their rooms, but at one point she said she had to wait two hours for ice to be brought to her room.

The woman said she and about 50 other sick passengers were the last ones off the ship once it docked, and were forced to wait nearly an hour in a room with no seating, forcing some to lie on the floor.

On leaving the ship, passengers were handed cards apologising for the outbreak and offering cruise credits. But the passenger said when she tried to contact the number, it didn't work.

She eventually found the right number, but the cruise company had yet to finalise an arrangement.

A spokeswoman for Royal Caribbean said that following the eight night sailing, the ship and terminal underwent an "enhanced cleaning and sanitisation", and that relevant health authorities were alerted.

She said of 2661 total passengers, 1802 guests and 859 crew, 175 reported feeling sick. While at sea, the cruise asks anyone with symptoms to advise staff on the ship as soon as possible.

"As well, all new guests embarking receive a letter at boarding that asks them to advise if they have experienced any gastrointestinal symptoms within the last three days – it is very important that guests advise us of any illness," she said.

A spokeswoman for the south east Sydney local health district confirmed they were contacted by the ship at the time of the outbreak.