Thirlmere is a large and very scenic lake alongside the A591 between Grasmere and Keswick. Helvellyn towers over the eastern shore while to the west conifer plantations dominate the fells. Thirlmere is a water supply reservoir providing Manchester with much of its supplies – with the result that water levels can drop dramatically over a dry summer. However at normal levels the lake is a spectacular wild fishery and for most of the year quiet and undisturbed.
Thirlmere holds brown trout, pike, perch and char. The trout are fairly numerous and average around 1/2lb with frequent larger fish and a few ferox up to double figures. When levels allow the water can be fly fished from the shore with the area around the feeder streams offering the best bet, particularly after a spate. Access is good, particularly from the numerous car parks on the western shore but fishing is not permitted along the southern shoreline from the mouth of Wythburn Beck to a point below Wythburn Church. This is a protected conservation area.
Boat fishing, traditional loch style is much more productive and best on overcast days with a good breeze. Most traditional patterns will catch and Black Pennell and Kate McClaren are currently the favourites. Don't deliberate too much - on the whole the trout are hungry and easily pleased - but can be lightening fast and you will miss more than you hook. There is a good hatch of olives and even a few mayfly but at other times fish are not inclined to show much on top. Boats may be launched from the car park at Armboth. Please note that outboards (petrol or electric) are not permitted.