Fly fishing has so many possibilities. One of my favorite is figuring out a lake, pond, reservoir. Your observation skills are required on a lake as much as they are standing knee deep in a stream. Presentation on a lake is as important as on a stream.
I frequently see lake fly fishers in their pontoon, float tube, raft etc. moving along, line extended behind and rhythmically kicking, drifting or rowing with only the slightest consideration given to a retrieve or to their position. We all do this at times while searching/discovering a new body of water. But, I would suggest that if you are out over 50′ of water with no discernible hatch/feeding activity you would be better served to move in toward the shoreline and attempt to study the contours of the lake. This may show you the structure and feeding zones where fish congregate for safety and food.
The drop is that area that transitions from somewhat shallow waters of say 10′ downward to deeper water. This drop off is prime in searching for trout that move up on the shoal to feed and move back off the shoal for safety and food as well. At a minimum work parallel to this drop and present your fly up on the shoal if hatch/feeding activity is apparent or work the fly down into the drop off area and slightly deeper.
Anchoring and fishing toward the drop (toward the shoreline) or up on the shoal can be productive. If you are not anchored, the wind or the torque of your casting can push you back out of the productive waters. This results in a lot of kicking or rowing to hold position and disturbances that may put the fish off the bite.
Sometimes the insect that is emerging, say Damsels or Gray Drakes, are actually moving toward shore to stage for their ‘hatch’. You would want to position yourself on the shore or in close to shore and cast out away from shore then slowly work your Damsel or swimming Mayfly pattern back toward shore to mimic the Damsels moving just below the surface toward the shoreline reeds, weeds and structure.
Here is a piece by Herman deGalat at HookFlyFishing that highlights several of these points on fishing the drop and the presentation.