Hector’s are among the world’s smallest dolphins and found only in New Zealand's waters, while only around 50 breeding Maui adults now remain there. Trubridge described their protection as “a matter of now or never, or they will go past the brink and won’t be able to recover”.
The 38-year-old freediver said he had never swum in the Cook Strait before, or carried out any similar endeavour.
“The whole time I was swimming, I was getting pushed in different directions, north and south and then north again, but in the last stretch I was getting pushed sideways and almost missed the headland,” he told Radio New Zealand.
“If I’d missed that one there was another current from the other side of the headland that could have pushed me straight out to sea, so I was lucky on so many levels.”
He said he had enjoyed the first few hours of the challenge but grown fatigued in the later stages as the water got colder and the currents strengthened.
Trubridge holds the AIDA world record of 102m, set in the Bahamas in 2016, in the Constant Weight Without Fins freediving category.
In the disciplines most relevant to his Cook Strait crossing he has set a personal best in competition of 237m in Dynamic Apnea, as well as 187m in Dynamic Apnea Without Fins.