Use a 3 gram float balanced with a single split shot, fasten a float stop to your line first, and make about a 1 meter length leader of 3-4 lb test line. Use a size 6 hook and thread the hook through so that the point is just sticking out. Adjust the float stop to make it about 2-3 meters of depth from hook to stopper. Play with the depth to find where they are hanging out. Cast into the outskirts of the pads on the right or left side of the lake. You can even troll wet flies for them. I used a carrey special and hooked into a ton of them. They are long from dorsal to ventral surfaces, so when they get to the top of the water they lie flat, unable to put up any sort of fight. Rather boring I must say, and the 19 inch cutthroat I hooked there was much more fun.
Good luck.