Swimming centres in the district are asking people of all fitness levels to dive in and raise money for Sport Relief.
The World’s Biggest Swim will be held between March 21 and 23 with people across the county making a splash for charity.
Everyone Active centres in Ongar, Waltham Abbey and Loughton are urging residents of the district to swim either 1.5k, 2.5k or 5k races.
The races can even be split up by teams.
For further information on the swimathon click here.