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:

1. Rubber (or band) powered - which are the simplest and cheapest to maintain, with rubber being the predominant type, and;
2. 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.

Uses of spearguns

Spears and spearguns have various uses:

• Sport spearfishing
  Spearfishing
  Spearfishing is an ancient method of fishing that has been used throughout the world for millennia. Early civilizations were familiar with the custom of spearing fish from rivers and streams using sharpened sticks....
  
  
• In tropical seas, some natives spearfish
  Spearfishing
  Spearfishing is an ancient method of fishing that has been used throughout the world for millennia. Early civilizations were familiar with the custom of spearing fish from rivers and streams using sharpened sticks....
  
   for a living, often using a home-made snorkeling kit
• As a weapon, as seen in works of fiction such as Thunderball
  Thunderball (film)
  Thunderball is the fourth spy film in the James Bond series starring Sean Connery as the fictional MI6 agent James Bond. It is an adaptation of the novel of the same name by Ian Fleming, which in turn was based on an original screenplay by Jack Whittingham...
  
  , A Series of Unfortunate Events
  A Series of Unfortunate Events
  A Series of Unfortunate Events is a series of children's novels by Lemony Snicket which follows the turbulent lives of Violet, Klaus, and Sunny Baudelaire after their parents' death in an arsonous house fire...
  
  and Hell Ride
  Hell Ride
  Hell Ride is a 2008 American feature film from Larry Bishop released under the "Quentin Tarantino Presents" banner.-Plot:Larry Bishop stars as biker Pistolero, the leader, or "Pres" of the Victors, a Southern California motorcycle gang...
  
  .
• This news item describes a rifle-like gun that fires a spear on a line; the spear has a wide hollow tip and on impact with the target (here, a killer whale), takes a core of skin and blubber
  Blubber
  Blubber is a thick layer of vascularized adipose tissue found under the skin of all cetaceans, pinnipeds and sirenians.-Description:Lipid-rich, collagen fiber–laced blubber comprises the hypodermis and covers the whole body, except for parts of the appendages, strongly attached to the musculature...
  
   as a biopsy
  Biopsy
  A biopsy is a medical test involving sampling of cells or tissues for examination. It is the medical removal of tissue from a living subject to determine the presence or extent of a disease. The tissue is generally examined under a microscope by a pathologist, and can also be analyzed chemically...
  
   sample and falls out. This type of device is more correctly described as a modified harpoon gun.

All spearguns have a trigger mechanism that holds a spear in place along the barrel.

Traditionally, rear-handle spearguns are popular in Europe and mid-handle guns were used in North America, however as spearfishing has developed as an international sport these distinctions have blurred.

South Africa

South Africa

The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...

n speargun manufacturers have improved speargun designs with the use of a rail along the barrel that prevents the spear from flexing under pressure from the rubber bands.

Accessories

The speargun can have:

• Buoy or float, tethered to the speargun or directly to the spear. It helps to subdue large fish. It can also assist in storing fish, but is more importantly used as a safety device to warn boat drivers there is diver in the area.
• Floatline, connecting the buoy to the speargun. Often made from woven plastic, they can also be a mono-filament encased in an airtight plastic tube, or made from stretchable bungee cord.

Speed rig

Here the spear gun is connected to a buoy via a float rope. After spearing a fish, the spearfisher detaches the float rope and uses a speed stick (a metal spike) attached to the float rope to thread the fish onto the float rope through its gills. The fish will then gradually slide up the float rope as the diver swims until it rests underneath the buoy. When shooting larger fish, the diver can let go of his gun and play the fish from the float line, giving the fish more room to tire and preventing it from tearing off the spear or dragging the spearfisher under the water.

Break-away rig

Here the spear shaft is connected directly to the buoy. It is loosely fitted to the gun as well while hunting, but after the spear is fired its force of movement detaches the line from the gun. The spearfisher is then able to subdue the fish from the buoy or float line while retaining possession of his gun. This is for two reasons. Firstly, the gun can be use to push off sharks or signal the boat driver, and secondly to prevent loss of the gun should the fish break the line, or should the spearfisher lose grip on the buoy. This setup can be used in conjunction with elastic bungee

Bungee jumping

Bungee jumping is an activity that involves jumping from a tall structure while connected to a large elastic cord. The tall structure is usually a fixed object, such as a building, bridge or crane; but it is also possible to jump from a movable object, such as a hot-air-balloon or helicopter, that...

-style rope and a body board style float with locking cleats. This respectively maintains constant pressure on the fish and allows the spearfisher to rest while being towed around. They can then gather the bungee line as the fish tires and lock it off in order to gradually pull the fish closer.

Reel on gun

Here the gun has a line reel like on a fishing rod. After spearing a fish, the reel unwinds, allowing the spearfisher room to play the fish. Reel setups are useful when ocean structures such as built up reef or kelp gardens prevent the spearfisher from towing a buoy.

Free-shafting

Here the spear shaft is not connected to a gun or buoy. This is more commonly associated with spearfishing on SCUBA where excess cable or line can be problematic. Also it can be used in the areas with exceptionally clear water, where underwater hunter can track his shaft after firing it. It is not used in turbid waters with poor visibility.

Riding Rig

Here, the spear shaft is connected to monofilament or other small high strength line, which is wrapped around the speargun, then connected to a larger, easier to handle rope which the diver holds in his hand. On the larger rope there is a loop on the end big enough for the divers thumb. The rope is placed on the thumb, then wrapped around the back of the hand. In this setup the spear is also totally free from the gun, allowing the diver to work the fish using the large rope, while keeping his gun safe. If the fish is too large to hang on to, the diver can tie it off or release it, only losing his spear and rope. This is used usually when fishing around oil rigs, or other hazardous diving such as hunting larger fish or in poor visibility.