There's doing a few lengths in your local lido, dodging inflatables and enthusiastic nippers. Then there's spending 157 days swimming around the coastline of Great Britain, immersed in water for up to 12 hours a day facing jellyfish, whirlpools and tidal currents of up to 12 knots.

If you're Ross Edgley, the latter is par for the course. The first person to complete this mammoth challenge, he had to swim around 20 miles a day – the length of the English Channel – depending on the tides, waves and the weather conditions.

A member of Bremont Adventurers' Club and all-round intrepid explorer, Edgley is the perfect choice for the latest instalment of Rear View, where we speak to the incredible people giving us a whole new perspective on the world around us.

The interview

Ross Edgley in training

When you spend that long in salt water, your tongue starts to disintegrate. I got sea ulcers on my shoulder and around my neck. They were worrying at the time as they could have brought an end to the swim, but they healed quickly afterwards.

I had to swim the Gulf of Corryvreckan in Scotland, where there's a giant whirlpool. Many ships have been lost there, and it's written in Scottish folklore. There was no option but to swim straight through it since going around would have added miles to the journey. I had to swim at a relentless pace to get through.

During my swim I ate 649 bananas. I was swimming up to 12 hours a day, so I often ate in the water. We relied on smoothies since they are easy to drink when treading water. Bananas are also great since they're so easy to peel and eat.

When I was in the Bristol Channel, a minke whale joined me for ten miles of the swim. It was circling me, blowing bubbles in my face and swimming below me. Matt, the captain, believed it was a female and she thought I was an injured seal as she kept me company all the way to Wales. As we approached the coast, the whale breached one more time as if to say goodbye and then left – it was incredible.

The ocean is relentless, and you have to be able to time things perfectly. You could be the best swimmer in the world, but if you try and swim against the current through the Pentland Firth (one of the strongest tidal currents in the world), you'll end up moving backwards faster than a dolphin can swim.

Edgley is an ambassador for Bremont watches. For more information, see bremont.com