Crummock Water is the biggest of the three connected lakes that comprise the River Cocker's basin, measuring about two and a half miles in length and slightly more than half a mile in width. Crummock screams to be fished from a boat, and they are (supposedly) available for rental, but only with oars.

This implies a lot of rowing for little fishing, particularly on a windy day with a high probability of excellent sport. Although the National Trust advises that no launching facilities are available, you are free to launch your own unpowered boat. On the positive side, fly fisherman will discover miles of accessible bank, but steer clear of the southern end due to the influx from Buttermere - unless you want waist-deep bogs.