A float when fishing does two jobs: it lets the angler know when his bait has been taken, giving him a visual point where the line enters the water. It also dangles the bait at a pre-determined distance between the top of the bottom and the bottom. As with every other piece of tackle, the angler must know what fish he is after and what the characteristics of that fish are in order to select the correct tackle.

Some fish are naturally suspicious of bait attached to a float. Although it appears to float invisibly in the water, the bait resists attempts to move it or swallow it. Some fish, particularly a luderick, will immediately release bait from its mouth when it feels the drag of a float from above. A float should bob on the surface in a state of neutral buoyancy. The slightest tug from below will be transmitted to the angler and will not alert the fish to its presence. The ideal use of the float therefore requires a careful balance between the weight of the float and the use of a splitshot sinker or weight.

The difficulty of using a line with a float is usually in the length of line between the float and the hook, which is hard to manage during casting. Ideally a float should be rigged so that it runs along the line and stops at a pre-determined point on the line with the use of a splitshot sinker or swivel. This point is the desired depth at which the angler would like his bait to dangle underneath the water.

The shape of the float is almost as essential as the weight or buoyancy of the float. The bobbing cork of the rock fisherman must be able to support the weight of the bait as well as the turbulence of the water washing back from the rocks. There is no need for it to as sensitive as the float of the estuary fisherman who would use a long slender float with a sensitive tip.

The bubble float is a favourite among trout and mullet fishermen. It is a clear, plastic ball with plugs, which allow the angler to partially fill the ball with water and hence regulate its weight and where it sits on the surface of the water. Some floats are designed to lie straight on the surface of the water and only stand upright when registering a bite from below. These floats are not popular however as they are difficult to locate and track before the bite. Luminous floats can also be used, however these are not popular either as the luminous fades after a short time.

Colours of a float are important only to the individual angler and the best is determined by their ease of sight in various types of water.

With the exception of the lying-down type of float, all other floats should ride upright in the water. If they don't, it is because they are either out of balance, or need an extra weight affixed to the line underneath them to draw them into an upright position. The bait may also be resting on the bottom, the water being shallower than anticipated by the angler.

To thread the float, simply pass the line through the eyelets of the float and then at the depth at which you want your bait to dangle, affix a splitshot sinker or other device to stop the running of the float along the line beyond that point. There should be just enough pf the float above the water to make it visible to the angler. Too much and the wind will catch the stem and blow it away. Experienced anglers can then watch their float and know instantly what is happening beneath the surface where their bait is. The float disappearing from view is a good indication the bait has been taken and time for the strike.