I'm swimming the 2 mile Serpentine Lake loop in Hyde Park on Saturday 19th September to raise money for Paz y Esperanza, a Christian human rights charity working in Latin America with many of the most marginalised people, including women suffering domestic violence, indigenous groups struggling to keep their lands, migrants and refugees and those who have suffered or are suffering political violence or state repression. I worked with Paz y Esperanza in Peru for many years and know their excellent work first hand.