New Zealand's South Island is a wondrous place. There are so many cool things to do. I thoroughly recommend swimming with the dolphins in Kaikoura with "Dolphin Encounters". Any concerns I had about jumping into the cold ocean in middle of winter were set aside once I had put on 10 mm of wetsuit, booties and head gear and began to sweat during the promo video.
After a short trip and equipment check I was super excited and a little wary after slipping off the back of the boat with my snorkeling gear as our group entered the ocean after a pod of dolphins was sighted by our guides. I treaded water for a few moments, finding it bizarre to be in the ocean looking at mountains with snow on them while scanning the swells for dolphins. And then they arrived, dozens of them, racing on swells towards us with their dorsal fins piercing the water, before diving below and around us.
They seem to enjoy making eye contact and I swirled around in circles as they raced around me, coming so close that I tried to reach out, but with a flick of the tail they were gone.
After half an hour of twisting and turning, marveling at the speed and grace of the dolphins, I clambered back onto the boat, not unlike an overweight seal, both stoked and exhausted.
NZ is a trail running mecca, but variety and experiencing nature in any way is highly recommended.
After the boat docks at South Bay, consider passing on taking the shuttle van back to the cafe and run back via Whale Bay and Point Kean viewpoint, home to numerous seals and enjoy looking across the bay at mountains rising literally out of the ocean.