The Foyle has 4 main tributaries, the Mourne, Derg, Strule and Finn, all fast flowing rocky rivers. The Mourne in particular can require deep wading for best results. Care is needed on some of the most attractive and productive pools of the Mourne and newcomers are advised to get adivce from a local angler or employ a ghillie since fly fishing only is permitted on some stretches. Spinning and worming may be allowed on others. The upper reaches of these rivers and also the Owenkillen and Glenelly, providespate river fishing. The Roe and Faughan are also fine spate rivers and attract those in pursuit of sea trout. Very fine brown trout fishing on the Strule and Derg. Camowen, Drumragh and Fairy Water offer the river trout angler an enjoyable day out.