I didn't think I could get any colder than I was in Bolivia until I thought it a good idea to go swimming in the Pacific Ocean one country up from Antartica.

I was right about it being a good idea.

The Kaikoura Canyon is one of the natural wonders of the world. About a km out into sea from the east coast of the island, the seabed suddenly drops by about 1000m leading to a massive canyon which is said to be home to the infamous giant squid.

We'd arrived in Kaikoura in the pouring rain (again). It was beating down so hard that we could barely see where we were going. I'd heard a lot of good things about Kaikoura and was hoping that I wouldn't be disappointed. The whole place was covered in thick cloud and it was that kind of rain that disabled anyone from stepping a foot outside without becoming completely swamped. And so it stayed - for two whole days until the sun came out to play, the clouds lifted and we got to see the place for the first time....

What a fabulous place. Walking along the beach you have to be careful not to trip over the seals or step on any bird's eggs.

We quickly got ourselves booked onto a whale-spotting trip. It was the wrong season for killer whales that visit the canyon annually, but we got a superb view of a couple of sperm whales.

Spotting the whales was cool but truly unforgettable was swimming in the canyon with a huge pod of dolphins.

I have never been so cold in all my life. When I first jumped into the water I started to feel faint and dizzy almost instantly and decided very quickly that I was going to have to get back out again – I really didn’t think I was going to be able to bare it. It was so cold it was stopping me from breathing - and that was wearing a full wet suit too.

However the minute I saw my first dolphin I completely forgot about the cold. They are amazing. There are so many of them! At one point I had two over my head, one beneath me and one more swimming round in a circle. My boyfriend, Tim and I worked out a double act. Apparently they like you to play with them by singing and ducking and diving – otherwise they get bored with you and swim off.

The rule is that we are there to entertain them – not vice versa. So Tim did all the ducking and diving while I swam in a circle and sang as best I could through my snorkel.

Most of the time I was just laughing. Just being around them was making me want to laugh and I couldn’t stop. We soon realised that my laughter was attracting them even more.

All too soon, we were being called back to the boat for the last time. Shivering with cold I drank my hot chocolate as an organiser shoved a hose with warm running water down the back of my wetsuit. It felt like someone was peeing down my back, but I wasn't complaining!

Swimming with those dolphins really was one of the best things I have done so far in all my life. Yes, it was organised, but this was no marine park. We were in the middle of the ocean over the 1000m deep canyon.

This is home to huge whales and giant squid. It’s bloody freezing and really hard to snorkel in – the waves are pretty big and scary. The weather had been so bad leading up to that day that we’d had to wait around a few days in order to be able to go. It cut into our time on the South Island, but I’m really glad we did. Some things are just worth the wait.