They come from all over the world to tackle the "Everest" of swimming - the English Channel.
Ever since Captain Matthew Webb's first successful Channel swim in 1875, thousands of swimmers have attempted to emulate his feat. Most are content to complete the swim, others are determined to set new records.
It all started in 1872 when JB Johnson tried to swim the Channel, but failed, abandoning his attempt after 1 hour and 3 minutes. Reading of his exploits, Captain Webb (1848-1883) became inspired to try it. Serving as captain of the steamship Emerald, he began training in 1873. On 12 August 1875, he made his first attempt, but was defeated by strong winds and poor sea conditions. Less than two weeks later, on 24 August 1875, covered in porpoise oil, he dived into the Channel from the Admiralty Pier at Dover. Although he was stung by jellyfish, and strong currents kept him off the French coast for five hours, he finally landed at Calais, recording a time of 21 hours 45 minutes.
On 24 July 1883, tempted by a prize of £12,000, he attempted to swim across the Niagara River below the Niagara Falls, but was swept away by the currents and drowned. A memorial to Captain Webb stands on Dover seafront.
Since then, interest has grown in Channel swimming, and there is always a waiting list of people booking places with pilots from the Channel Swimming Association and the Channel Swimming and Piloting Federation in the hope of adding their names to the list of those who achieve it. So far 1,619 swimmers have made a total of 2,123 solo crossings.
Alison Streeter and Kevin Murphy
The Queen of the Channel - and the person who has swum it more times than anyone else - is Alison Streeter MBE, who lives in Dover. Alison has made 43 successful solo crossings, including a three-way swim, and has also participated in six relay swims.
King of the English Channel is Kevin Murphy, with 34 solo crossings.