More than 60 people, mostly Afghans, were saved by French and British rescue teams, including Idris and 15-year-old Fawad.
"When (the boat sank), people were screaming, it was a very difficult moment.
The survivors helped each other by taking turns in clinging to or sitting on what was left of the boat, Idris said.
The Channel between France and Britain is one of the world's busiest shipping lanes and currents are strong, making the crossing on small boats dangerous.
"I was fast losing the strength to swim, but I kept trying very hard to keep afloat," Idris said.
Persons:
Idris, Pascal Rossignol, Fawad, Rishi Sunak, Sheree Sardar, Ingrid Melander, Janet Lawrence
Organizations:
REUTERS, Reuters, United Kingdom . Conservative British, Thomson
Locations:
Britain, Calais, France, CALAIS, England, British, Afghanistan, London, Iran, Syria, United Kingdom