No sir. If you are fishing stillwater, your leader should be, Id say AT THE MINIMUM, 9 feet. I personally use 12-15 foot leaders on stillwaters. That is long enough to keep well away from the fish with the fly line, and easy enough to cast. I know some guys use 20-30 foot leaders, but for us beginners, that is a bit excessive and really not necessary. 10-15 foot should be ok, depending on how you cast.
As well, if you are on a lake, and just casting your fly out, it will just sit there and float. Strip it fast and hard to get it to sink, then continue with a slower retrieve. Retrieves are funny though, its a very non-scientific aspect of fishing nymphs and wet flies. One day I could NOT get a fish to bite anything. I figured they were taking emergers, which I had no flies that represented that stage. I put a shot on my leader, with a pheasant tail nymph, and stripped pretty hard to get it rise in the water, got a bite on the second cast. Sometimes, you need a real slow retrieve. Its a lot of expermenting
But back to the topic. If you have a muddler minnow and leeches that float, trying mucking them up in mud first if you can. Get it all in there. That should help. Aside from that, split shot, bead head, or lead wraps (if you tie your own flies.)
Ive also found that when switching flies, Ill cast in the opposite direction I want to fish, and cast the fly straight into the water. No nice roll over. Just shoot it into the lake, and then its usually good to go. I suppose you could dunk it first though, and that would work. And scare fish less.