Find a venue locally for Open Water Swimming.  Please check with organisers on requirements and experience to swim.

Hinchingbrooke Park, Huntingdon.  Friday evenings, 6pm to 7.30pm, last entry 7pm.  Must pre-register (membership/swim disclaimer forms) through organised by TRI-BRJ Club.

Histon Lake, Cambridge (back of Holiday Inn, Histon off the A14).  Friday evenings from 6pm.  More info on Cambridge Tri Club website

St. Neots River, St. Neots.  Various sessions: Monday, Wednesday & Friday.  See the Nicetri website for more details