Float AND Buoy (Fishing Helper)

Fig: Float & Buoy

Floats are used to keep fishing net in a proper shape in water, whereas, buoys are attached to the fishing gear to show its location.

Required properties of float and buoy:

a) Great buoyancy
b) Less decrease in buoyancy under high water pressure
c) Long age
d) Ease of manufacturing and modeling
e) ample supply and low cost

Material and shape of float and buoy:
Wood, cork, bamboo, glass ball, iron ball, rubber ball have been used as material of float since the old age. Now the floats are made of synthetic resin in most cases. The common floats are cylindrical, globular or oval.

Bamboo poles with flag, radio buoy, lamp buoy and wooden barrel are used besides buoy made, of same material as that of float.

Float & Buoy Made of' synthetic resin:

The principal material for float and buoy is polyvinyl chloride. The porous type is common as float and the hollow, type and balloon type is widely used as buoy.

Float vs Buoy:

As compared to wooden made floats and buoys; the merits & demerits are:

Durability against corrosion                Stronger
Weight for unit capacity                      Lighter
Buoyancy for unit capacity                 Greater
Resistance against water pressure        Stronger
Proof against chemical                         Stronger                      
Resistance against abrasion                  Weaker
Ease of handling                                   Easier because lighter

Calculation of buoyant fore

When a capacity of a float is V cm3 and its weight in air is Wg, the buoyant force (F gram) of this float will be obtained by the following formula:

F = (V-W), if the sp. gr. (C) of the material is known,
Then, V=W/C                     Therefore, F = (w/c) –w
             = W (I/C – 1)

SINKER
Required properties of sinker

a) Great sinking force (underwater weight)
b) Ease of manufacturing and modeling
c) Amply supply and low cost

Material and shape of sinker

Sinkers are made of lead, iron, porcelain, stone or concrete block. The typical shapes of sinkers are cylindrical, drum-like, globular & boat-like.

Calculation of sinking force of sinker

When the capacity of a sinker is V cm3 and its weight in air is W gram, the sinking force (S gram) of the sinker will be obtained by the following formula:
 
S = (W-V), if the sp. gr. (C) of the material is known,
Then, V = (W/C),
Therefore, S = W – (W/C) or, S= W (I – I /C)

The sp. gr. of the popular sinker materials are given below:

• Lead            11.34 Iron 7.86
• Porcelain      2.50 stone 2.60
• Cement         3.00 Sand 1.80

Thus in fishing world, Float and Buoy works in operation.