Lough Derg is a freshwater lake in the Shannon River Basin. It is the second-biggest lake in the Republic of Ireland and the third-biggest on the island of Ireland (after Lough Neagh and Lough Corrib).

It is a long, narrow lake, with its south-west shore in Co.Clare, north-west shore in Co. Galway, and Tipperary to the east. It is the southernmost of three large lakes on the River Shannon; the others being Lough Ree and Lough Allen. Towns and villages on Lough Derg include Portumna, Killaloe & Ballina, Dromineer, Terryglass, Mountshannon and Garrykennedy.

At its deepest, the lake is 36 metres deep and covers an area of 130 km². Close downstream from where Lough Derg empties into the Shannon are the falls of Doonass, the largest fall on the otherwise gently sloping river.

The chart used is from the Admiralty archives. It is set on a black background and is finished with a charcoal mount and black frame.


  • Location: Lough Derg, River Shannon, Ireland
  • Chart: Admiralty, UKHO, classic B&W
  • Surround lighting: No
  • Frame: Black, 600*600mm