Fishing and Gear Technology

Unit 7 - Floats and sinkers

7.2.Types of Floats

7.2.2.High Density Floats

• Glass: They are made in the form of sphere. This is covered by netting to facilitate fixing and for protection. However increases the drag while towing. They do not absorb water and can withstand pressure upto400 m depth. Big glass floats are used in lines and traps.
• Aluminium floats: These are made up of two halves and joined by means of welding at seams. They are more buoyant than glass and can withstand pressure up to 80m. Mostly used in trawls and gillnets.
• Steel: They are made in two halves and are welded together at the seams. They are not very popular. The buoyancy is reduced due to thick walls. Rust also get accumulated.
• HDP: These are useful in deep sea fishing up to 250 m. Not corrosive.
• GRP: Like HDP, GRP floats are expensive and not readily available. They are highly buoyant and can withstand pressure up to 400 m.