"It’s not a challenge. It’s just a good day for a swim."
Mr Caughlin (50), who lost his right arm in a swimming accident eight years ago, swam around the island from St Clair on Saturday with friend Gabor Langyel.
While conditions were choppy, the swimmers had little trouble completing the circuit in 1hr 45min.
"We’re used to it. We have a windy beach in Northern California, so we get a lot of wind chop," Mr Caughlin said.
"We had some texture out there, as we say, not really giving you an easy swim of it.
"It’s just fun. Most people would hate what we were doing, but to me it’s a lot of fun."
Mr Caughlin is from Halfmoon Bay in Northern California and has been taking a variety of papers at the University of Otago for the past two years.
On Saturday night, he was planning to go out for dinner and relax.