Coniston Water is located in Coniston in Cumbria, Lake District its over 5 miles long with a maximum depth of 56m with the most of the diving attractions located between 10m - 30m making this a great site for all levels, a popular diving spot is off bailiffs wood, its approx 1Hr 40 min from Canary Divers shop.
Dave one of the Canary Instructors has kindly written this description of diving at Coniston Water and some useful links.
You can enter here but it's quite steep, much better to turn left out of the car park and walk down the road for 20 metres or so
When you get to the beach (pebble beach) there's a large rock just in the water, depending on the water level depends if you can use this to lean on to put your fins on. When we went the water was a little lower so the rock was only just in the water and we had to move further into the water to don our fins.
If you take a bearing directly across the lake from the rock then descend you should get a shallow sloping bottom to a shelf running along the water at about meters. There should be a man made pile of rocks under you as you descend and an old metal mil urn. What we do is then carry on with the bearing descending to about 10 meters where there's a droop of to about 20 meters or so and then a shallow descent to whatever depth you want. Be careful though as there's lots of silt that can easily be disturbed. At about 28 - 30 metres there's a few gnomes. We then turn left along the wall gradually shallowing up until we get to the 6 meter shelf then double back along the shelf towards the man made pile of rocks which signals the entry point. There's all sorts of items on the shelf (bath, toilet etc) to have a look at. Note, it's important to deploy a tied surface marker buoy at the start of the dive as there's boat traffic on the water and the passenger steamer likes to get quite close to the shore when there's no buoy deployed, I normally tie the buoy to the milk urn mentioned earlier.