Wednesday, 4 July 2012
What do I need to start Spearfishing Part V: The Speargun
A speargun is an underwater fishing implement designed to fire a spear at fish.
The basic components of a speargun are: A spear, a stock/barrel, and a handle/grip containing a trigger mechanism. Spearguns are usually from .5 m to 2 m (1.5 ft to 6.5 ft) long, round or roughly rectangular from 28 mm - 75 mm (1 in to 3 in) in diameter/width.
The two most common types are:
Rubber (or band) powered - which are the simplest and cheapest to maintain, with rubber being the predominant type
Air powered (Pneumatic).
- Rubber powered ones come in two types: those made from wood, and those of sealed tubing metal or composite and/or a combination of these materials construction: referred to as the Stock or Barrel respectively.
Those of a tubular barrel variety have separate "muzzles" fitting in or over one end of the tube, for attaching the rubber bands; whilst others (usually those made of wood), mainly have the bands passing through a horizontal slot in the stock.
A rubber powered gun, besides the barrel, has the following parts:
A spear (being a steel shaft slightly longer than the stock/barrel of from 6 - 10mm in diameter, which lies on top of the barrel or in a track or groove on the top), and a trigger mechanism to engage the spear (usually in or near a handle or grip at or near the rear) to keep the gun in a loaded state of readiness when it is loaded.
Such loading is from one or more latex rubber bands (usually tubing)- which provide the propelling force - and are about one third of the barrel length and from 9 – 20mm in diameter, being attached to the front of the gun.
The ends of these bands have ‘bridles’ or 'wishbones', (which are usually metal or synthetic cord) fitted to them and when these bands are pulled by the diver to engage the 'wishbones' in notches in the spear or 'fins' welded on the top at the rear just before the trigger, the gun is loaded.
- A Pneumatic gun differs from a rubber model in that it has a thicker spear that goes inside a sealed internal barrel encased in a hollow sealed outer casing that contains the air which is at ambient pressure until it is pumped up by hand to a pressure usually equal to one strong rubber band. The trigger mechanism (which is at the back of the gun has a handle/grip below it or mid-way up the gun). Once at the required pressure the spear is forced down the barrel to engage the trigger mechanism and is then loaded and ready. There will usually be a strong line at least twice the length of the gun connecting the spear to the front of the gun. When loaded great caution must be exercised as the speargun is now a dangerous weapon. Without a trigger, rubber bands or air pressure the speargun cannot be loaded and therefore cannot function.