Kawerau Jet and Princess Cruises were diverted from commercial operations to rescue the kayakers.
College chief executive Charlie Phillips said a group of 25 adventure tourism management students, aged from 18 and 20, were on the final leg of an eight-day outdoor leadership programme when the four students got into difficulty.
A German woman, two Swedish men and a New Zealand man were kayaking about 100m offshore when a fast-moving southwesterly front hit, tipping the four kayakers into the chilly lake at 3.15pm.
"They would have been in the water about two minutes - if that," Mr Phillips said.
After pulling the four from the 10degC water, the college group - led by guides from Adventure Southland - rafted together and reached Seven Mile.
The group came ashore on the treeline where guides made a mayday call to Kawerau Jet.
Queenstown Lakes District Council harbourmaster Marty Black said TSS Earnslaw was also diverted as it steamed for Walter Peak.
"It could have been a lot colder in the water but they all had wetsuits and proper gear on. But no matter what time of the year you go into Lake Wakatipu, it wouldn't take long for someone slightly built to get hypothermia," Mr Black said.
The 25 students were taken to Sunshine Bay from Seven Mile where the four cold, soaked kayakers were put into police cars to warm up.
Within 20 minutes of landing, the students were back at the college lodge in Frankton for hot showers.
"The students did really well and the guides were outstanding - everyone's safe," Mr Phillips said.
