"We like to take them out after they've been at school for three or four weeks, purely to get them out to see Whanganui and to have a social occasion outside of school."
The students are from Thailand, Hong Kong, Korea, Vietnam, China, Japan, Taiwan, Fiji, Chile and Germany and are studying at Wanganui Collegiate to pass NCEA.
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The event has taken place for all five years of Ms Austin's involvement, except for last year when it had to be cancelled due to bad weather.
Ms Austin said the only worry this year was the water.
"Our main worry is with these students not being used to swimming in the sea," she said.
"We have quite a nervous time while they're all swimming in the sea, so we used the Whanganui Surf Lifesaving Club. They were fantastic and put on four staff for us."
Director of international students Alan Richardson played chef for the day, grilling chicken patties and sausages, followed by toasted marshmallows in chocolate biscuits for dessert.
Ms Austin said that throughout the day there was "lots of eating".
"They loved the afternoon out of school, they loved going to a different place, mixing together and having different food from the dining hall."