Crummock Water is the largest of the three linked lakes that form the catchment of the River Cocker and measures some two and half miles long and just over half a mile wide.
Crummock cries out to be fished lochstyle from the boat and they are (apparently) available to hire, but only with oars. This means a lot of rowing for not much fishing, especially on the sort of breezy day when the chances of good sport are high. You are permitted to launch your own unpowered boat although the National Trust advise that no launching facilities are available.
On the plus side fly anglers will find miles of accessible bank but avoid the southern end with the inflow from Buttermere - unless you happen to be a fan of waist deep swamps.