Loch Maben, as far as i know, contains no carp. There is a loch near by that does, but they are few and far between. A better bet is to fish some of the waters in Dumfries and Galloway. There are a few her, run by the Palakona Guest house. He has several waters containing crp, or, travel another hout north to Lanak for one of the best waters in Scotland. Loads of doubles with a record of 24 pounds.