Southern Discoveries nature guide Dave Newman said the numbers of the penguins, known as tawaki, were encouraging.
"There's more penguins this year than we saw last year, which is really positive for the colony and great for our guests as there are only up to 3000 breeding pairs in existence."
The penguins have been seen by tourists aboard the Encounter Nature Cruise as it comes close to the colony in Penguin Cove, where the penguins make their homes during the breeding season from July to November, and again between January and March to moult.
"We'll expect to see the penguins here until November when their chicks are ready to head out to sea," Mr Newman said.
"There's a real buzz when we first start seeing the penguins.
They're a very special bird as they're so rare. We're so lucky to be able to see them. New Zealand is visited by 13 of the world's 18 penguin species, and of those only three breed on the mainland.
"They come ashore and work their way into the thick rainforest, building nests ... and forming colonies of up to 10 pairs."