AlbaSurf,
Basically, presentation is just the way the fly is shown to the fish, whether trout, bass, bluegill or tarpon.
A dry fly is not always a terrestrial, but can also be an aquatic insect such as a mayfly or caddis fly when in their adult stages. In most (there are always exceptions to any rule) situations the dry fly is cast upstream and allowed to “dead drift” with the current and wind the same as the natural insect. To achieve a dead drift you must pay attention to the currents and winds so that the line and leader don’t affect the direction or speed of the fly. Most aquatic insect imitations are cast so they land lightly on the water, just as a natural would. Some terrestrial imitations, grasshoppers, crickets, sometimes get better attention by the fish if they land on the water with something of a plop, much like a wind blown natural bug would land.
Though a lot of people fish wet flies cast downstream and across, then swung on a tight line across the current, I, personally, like to cast the upstream, much like a dry fly. I allow the fly to come even with me, much the same as I would a dry fly, then allow the fly to continue past me until it swings on a tight line across thee current. I can cover more water with just one type of fly that way. I fish most of my wet flies on a floating line. What kind of dubbing is used, as well as the hook wire diameter, and the type of hackle will determine whether the fly floats or not. A waterproof natural (muskrat or beaver)or synthetic dubbing (fine and dry or superfine) , on a fine wire hook with stiff rooster hackle will float high and dry, while a water absorbing natural (hare’s ear, mole) or synthetic (Synthetic Living Fiber, Quick Descent) dubbing on a heavy wired hook and a hen or game bird hackle will sink below the surface. If those things don’t get your fly deep enough, weight can be added to the fly or leader to get it deeper.
If the fish are visibly feeding on the surface I will try to match the type of bug they are eating and fish dry flies. If they are not actively feeding on the surface I will fish wet flies (in my case upstream also) and try to target where in the water column the fish are holding.
There are a couple of ways to manipulate the fly to entice a strike. First, with a dry fly just a quick tug (like an inch or so) on the fly line will impart a little action into the fly. Mostly though, if you drift the fly naturally through the fish’s feeding lane that will be enough to bring the fisih up to eat your fly. With wet flies, once they are on the downstream swing you can use what’s called the Leisenring lift. Just before your fly reaches where you think a fish is holding, let the line get tight between the rod tip and the fly. This will cause the fly to rise in the water column often triggering a strike as the fish thinks a tasty morsel of food is about to escape. You can also strip in line. This is just a series of tugs with your line hand to bring line and the fly back toward you. You can also use a figure “8” retrieve by rolling your hand in the line in a fugure “8” motion, slowly bringing line in.
I have a couple of suggestions, one is to hit the Beginning Fly Fishing section here on FAOL ( http://www.flyanglersonline.com/begin/101/ ) A lot of your questions will be answered there. Another is to check out the chatroom here on FAOL in the evenings. There are many experienced fly fishers/tiers that visit the chatroom and they will do everything possible to help a beginner.
My last suggestion is to find a copy of The Curtiss Creek Manifesto, it’s is a very readable book with a ton of information for the beginning fly fisher. Whenever I hellp someone getting started I try to give them a copy of the book. It’s really very good.
Hope that helps a bit.
REE