Swimming with Tarka?

There was a story today on the BBC news about a drive to encourage lake and river swimming in the UK (almost as an extension to the 'right to roam' for walkers). One of the locations mentioned was the river Dart ("where swimmers can share the river with otters"). It is appreciated that swimming is healthy exercise (so long as one avoids dangers such as currents, rocks and Leptospira) and river swimming opens up commercial possibilities to land owners but otters are unlikely to share the locations with river swimmers. Disturbance (by humans) is one of the factors that was implicated in the UK decline of this species in recent times.