Lol , it's not cheating using indicators, and you'll be surprised how many takes you get with them.
Floating lines will let you fish your fly at any depth you need to be at on most of our waters , as folk have said , just use a longer leader and a sinking fly , but if the fish are in a chasing mood and want the fly pulled fast it's hard to do with a floating line if the fish are 4 or 5 feet down , the fly (even a weighted one) rises to the surface as you pull the line. That's when a sinking line is best , the whole line sinks parallel to the surface and you can count the seconds it has been sinking before pulling it back.
So, if you cast out your sinking line and count to 5 and the line sinks to 2ft then start pulling , the fly will come back to you 2ft down all the way , if you count down to ten it will come back at 4ft and so on.
There are different sinking lines though , some sink very slowly and some sink very fast , unless you want to fish 30ft down don't bother with a fast one , get an intermediate or a very slow sinker , it just means you have to wait a little longer for it to sink deeper.
You aren't wasting your time fishing just with a floating line, even if the fish aren't rising they are rarely very deep , try weighted lures or flies with different lengths of leader , fish with just one fly on the end of a ten foot leader and pull it back at different speeds , very slowly (and I mean VERY slowly) for a few casts and gradually get faster every few casts till you get a take , then remember how fast you were pulling and keep it at that for a while. Or try a slowly sinking fly on a ten foot leader and cast it out , straighten the line up and just let it sit there till you see a pull on the line , SEE a pull , don't wait till you feel it. Or put an indicator on the leader about 4ft from the fly (preferably a flexi bloodworm)and cast it out and just wait , if you are patient enough this virtually guarantees a fish. try different depths if 4ft fails to get a take.
Whatever you do ....... have fun
Ray