Derwent Water is a stunning lake nestled in the heart of the Lake District in North West England, situated immediately south of the historic market town of Keswick in Cumberland. As the third largest lake by area in the region — after Windermere and Ullswater — it stretches 4.6 kilometres in length with a maximum width of 1.91 kilometres and covers an area of 5.4 square kilometres. The lake is fed and drained by the River Derwent, which continues northward through Bassenthwaite Lake before eventually reaching the Irish Sea at Workington. Surrounded by dramatic fells and offering exceptional scenic beauty, Derwent Water is a genuinely productive fishery. Unlike most of the larger lakes in the region, it is relatively shallow, averaging just under twenty feet in depth — a characteristic that drives higher biological productivity and supports a notably rich biomass compared to its deeper counterparts.