The ideal main line for float fishing should be relatively buoyant and offer good abrasion resistance. Since all fishing lines sink, it is best to choose ones that will sink relatively slowly. Thinner diameter lines are also preferable because they are less affected by the wind and cut through the water's surface tension more easily when mending the line.
Many avid Steelhead anglers are now using high visibility lines. Hi-vis lines help anglers keep track of their line, as well as their floats, improving float control. These lines also help reduce the chance of other anglers accidentally casting over your line when fishing in close quarters.
When connecting the main line to the leader use a premium quality micro-swivel to ensure the strongest connection possible. Because all monofilament lines tend to cut into themselves, line to line knots generally make a weaker connection.
A number of anglers prefer running a "shot line" between the main line and the leader. The idea behind using a shot line is to allow the angler to carry a variety of pre-rigged lines that can be easily switched as required, without much downtime on the river.
The shot line replaces the section of main line that would normally run underneath the float to the leader. A typical set-up would run 8-10lbs main line to a swivel under the float, then a length of 6lbs shot line to a second swivel and finally a length of 4lbs leader to the hook. Running a fluorocarbon shot line in conjunction with a fluorocarbon leader gives the added advantage of making the set-up below the float virtually invisible. This is particularly useful when running a high visibility main line.
Matching the strength of the leader to the main line is essential to avoid unnecessary loss of fish or tackle. As a rule of thumb, use a leader that is rated roughly 2- 4lbs less than the main line. This ensures that the leader will break before the main line, avoiding the loss of the float. When using a leader much lighter than the main line, the main line will hardly stretch to cushion any impacts. This forces the leader to support an excessive amount of stress when fighting a fish or setting the hook, and inevitably results in a break-off.
Leader length can be a confusing issue and every angler has a different view on the subject. When choosing your leader length consider these three factors: Depth, Clarity and Sensitivity.
Depth - An easy rule of thumb is to run a length of leader equal (at least) to the depth of the visibility of the water. In other words, if you can only see two feet down, run a leader at least two feet in length. This ensures that the fish will not see and be spooked by the line or split shots before it has a chance to strike the bait.
Clarity - In very clear river systems, it is impossible to run a leader long enough to prevent fish from seeing the main line and shots. In this situation, run the longest leader possible that will effectively present the bait to the fish and still remain comfortable to use. Conversely, in dirty water conditions, a very short leader can be used. In general this leader should be no shorter than 12" to 18". Using a leader shorter than this will hinder the presentation as the bait is tethered closely to the split shots and won't react naturally to underwater currents.
Sensitivity - It is important to note that longer leaders make float fishing set-ups less sensitive, as tentative bites will often fail to register on the float. This occurs because the float will only register a bite once the last split shot on the line moves. Many European float fisherman refer to the last shot as the "Tell Tale" shot. A shorter leader will register a clear take on the float sooner, resulting in less lost fish.
The Tell Tale Shot - Imagine a fish picks up the bait at the end of a 4' leader and swims slowly upstream creating a bow in the leader line. The float and the shot line remain virtually unaffected as there is only a slight slackening of the line. Once the fish swims 4' past the float it will finally move the last or "Tell Tale" shot and register a clear take on the float. In this situation, the fish has taken the bait and moved 8' without affecting the float. This gives the fish too much time to drop the bait.
In the above scenario, the only indication that a fish had taken the bait would have been the float riding slightly higher than normal with the slackening of the line. This is a "lift bite". Very keen anglers will often set the hook if they notice this happening. "Lift bites" mostly occur at the back of a pool where fish tend to strike the bait and hold in place or move upstream, rather than turn and swim out of the pool. These takes often come as a surprise to anglers who suddenly realize they have a fish on when they start reeling up their line for the next drift. All too often the fish is lost because they haven't seen the "lift bite" and had the chance to set the hook properly.
Ideally if you run the correct length of fluorocarbon leader, the bait will be presented naturally, the fish will not see the main line, shot or leader and the float will register clear takes.