D

Dampen
A fly rod's rate of recovery from a cast

Dapping
A method of stillwater fishing practised mainly in Scotland and Ireland. A large well hackles artificial fly is cast out or allowed to be blown out with the wind, and lowered on to the surface. Longish rods with short floss lines are favoured so that only the fly touches the water. In addition to specialist patterns, densely hackles Crane-flies, Mayflies, the Pennell series and Palmers are also suitable.

Dead drift
Technique that allows the fly and fly line to drift naturally in a current, without drag.

Deer Hair
Deer body hair fibres are stiff and hollow and can be spun on to the hook shank as a body or head material to make an extremely buoyant floating pattern. The most common use for the material is in the Muddler head. Deer hair fibres are laid on the shank where the head is to be formed. Strong thread is wrapped round and, as this is done, the fibres are moved completely to surround the shank. The thread is pulled tight and the bires stand erect. This is repeated until sufficient hair is tied in. The hair is then trimmed to the cone, dome or ball shape required. Some tyers prefer to leave a trailing hackle of some of the longer fibres. Whole bodies can be constructed by using some of the small hairs and trimming them much narrower. Such bodies are virtually unsinkable.

DEET
Short for diethyl-meta-toluamide, the chemical most effective in the repellents used as protection against insects

Density
Refers to the weight of a fly line, leader and fly compared to the weight of water. For example, high-density fly lines are heavier than water and will sink; low density lines are lighter and will slowly sink or even float.

Detached Body
Separate bodies tied on to the shank and not around the shank in the usual manner. They can be built up around a stiff piece of nylon monofilament, bristle, cork, feather quill, or be a specially made plastic body. Detached bodies are often used in Mayfly artificials. See under Hooks.

Diamond Braid
Metallic braid material used for tying streamer and nymph bodies. Excellent for woven nymphs. Reflects light well and provides a segmented body appearance

Direct drive
Type of reel that has the handle connected directly to the spool, which revolves as the spool does in both directions

Disc drag
A type of braking system inside a fly reel, designed to put a great amount of smooth pressure directly on the reel spool. This type of system is often used when fishing for large, heavy fish.

Ditty bag
The fly fisherman's "handbag"; i.e., auxiliary "duffel" type bag for miscellaneous items carried while fly fishing

Double click
Reel that has two pawls

Double haul
The ultimate way to generate maximum line speed and distance in the pick up lay down cast. A haul is performed on both the back cast and forward cast to produce a great amount of tension on the fly line, as tension creates line speed and distance.

Double taper fly line (DT)
A fly line that has the same thickness and taper on each end of the line. The midsection, the belly, does not thin out. If you cut the line in half, the two pieces would be mirror images of each other. These lines are tougher to cast than weight forward lines but can be economical: if one end of the line is damaged, the line can be reversed.

Drag
The undesirable effect caused by the flow of water current pulling on the fly line that results in the fly "dragging" behind in an unnatural manner

Drag coefficient
Term used to describe the start-up friction a fish has to overcome before the reel's drag system allows the spool to feed out line

Drag system
A component of the fly reel that puts tension on the revolving spool of fly line. Tension, or drag, is needed to tire a fish after it is caught and attempts to get away in the opposite direction. A drag system will also prevent line tangles when you strip line from your reel during casting.

Dress
The application of substances, such as flotant, to the fly line, leader or fly

Dropper
The fly that trails behind the point fly in a two-fly rig. It is tied between the tippet and the point fly.

Dropper knot
A knot used to provide a loop off of the leader or fly line to which can be attached an additional fly or weight

Dry Fly
An artificial fly constructed so that it floats on the water surface. It represents the adult stage of the insect's life or a terrestrial.

DRF
Depth-ray-fire. See Fluorescence.

Dubbing
The technique of twisting fur or wool fibres round the tying thread and winding it around the shank to build up a body. The fibres may be picked out with a dubbing needle to represent the legs or wings of the natural. For a shaggy body of longer fibred material the fibres should be placed in a dubbing loop at right angles to the thread and twisted with the aid of a dubbing whirl.

Dubbing Brush
Dubbing that has been twisted between two fine diameter soft copper wires for ease of wrapping.

Duck
Grey wing quills are used for winging and are easily dyed. Also see Mallard.

Dun
The first winged state, known as the sub-imago, of the upwinged flies, the Ephemeropterans. Also used to describe a duller colour shade, ex: blue-dun.

Duncan loop knot
A knot used to provide a small, open loop in the leader tippet at the point where it is tied to the fly; to enhance the freedom of movement of the fly