Has anyone else tried Bodenham lake in Herefordshire (a few miles south of Leominster)?  This is the largest open water site in the county and in a good summer the water can get quite warm.  At some places the water gets deep very close to the shore but there are little coves where the water is shallower (and warmer).  Best times are mid afternoon when all the dog walkers have gone home.  Parking is easy and it is only a shortish walk to plenty of good locations.  Most private (but deep water) is between the lake and the R Lugg which flows very close by.  The shallower places are less private but you are unlikely to be disturbed.  I have been to all locations on about 9 occasions.  Well worth exploring.  2015 was too cold but 2013 and 2014 were vintage years.