Adam Walker, from Lincolnshire, swam across the Irish Channel on Wednesday to complete his seventh and final swim, and marking the end to a remarkable journey that has spanned six years.He crossed the channel from Donaghadee, Co Down, to north of Portpatrick in southwest Scotland - a distance of 21 miles in 10 hours 45mins - to finally complete his epic Ocean's Seven journey.He is only the second person in the world to complete all seven swims that make up the Ocean's Seven challenge on the first attempt. Overall, only four people have ever completed the challenge.In his battle from Ireland to Scotland on Wednesday, Adam faced a number of challenges including strong currents, hypothermia-inducing water temperature and large pods of jellyfish.He said: "I just can't believe that I've finally done it! I am ecstatic to finish seven out of seven swims on the first attempt. This swim was the last of the hardest seven ocean swims on the planet and to know that I am the first British person ever to succeed is a truly amazing feeling!"The Irish Channel is the toughest on paper with Lion's Mane jellyfish and hypothermia the two factors which stop most people from crossing. The temperature is only 12 degrees (54 ºF), too - when a swimming pool is 29 degrees (84 ºF), to put it into perspective."His Ocean's Seven quest has also includedCHAR(13) + CHAR(10)English Channel, 21 miles (34km), July 2008 - completed in 11 hours 35 minsStrait of Gibraltar, 8 miles (13km), July 2010 - completed in 9 hours 39 mins (British record) and the first Brit to swim from Spain to Morocco and back againMoloka'i Channel, Hawaii, 26 miles (42km), July 2012 - completed in 17 hours 2 mins after overcoming tiger sharks and first Brit to cross successfullyCatalina Channel, USA, 21 miles (34km) October 2012 - completed in 12 hours 15 mins in darkness and fogTsugaru Strait, Japan, 12 miles (19km), August 2013 - completed in 15 hours 31 min, the first Brit to swim across the unpredictable channel through dangerous marine lifeCook Strait, New Zealand, 16 miles (26km), April 2014 - completed in 8 hours 36 mins after being rescued from a 6ft shark by dolphins"I have been stung by a Portuguese Man 'O War, which made me lose the feeling in my spine after more than thirteen hours of swimming, and I had to carry on for over three hours in agony and almost paralysed. I've also been chased by sharks. I've had everything thrown at me."These swims have given me so much; they have changed my life. Seven years ago, I hadn't had a swim for 10 years, I was overweight, I wasn't doing much sport and I was a little depressed. Now I am classed as one of the best open water swimmers in the world and I feel I can conquer anything!CHAR(13) + CHAR(10) CHAR(13) + CHAR(10)"I believe you can achieve anything in life if you want it bad enough. No matter what your dreams are, with hard work and determination you can achieve them."CHAR(13) + CHAR(10) CHAR(13) + CHAR(10)He added: "I would like to thank everyone for all the support I have had over the past seven years to make this dream a reality. Without this, completing the challenge would not have been possible."