Techniques and Guidelines
It is difficult, at best, to identify an exact technique to use in every case. Each individual spearfisher has a personal style, and a different technique is employed for each type of game sought. These techniques can vary from one geographic region to another. In other words, a technique that works well in one body of water or with a certain type of fish may not work well in another body of water or with a different species.
There are, however, certain techniques and strategies that apply to all regions and species. When shooting, being neutrally buoyant is key. You should always shoot down and within line of sight so the shaft does not penetrate something or someone for which it was not intended.
Never shoot if you cannot see the other side of the target!
There are, however, certain techniques and strategies that apply to all regions and species. When shooting, being neutrally buoyant is key. You should always shoot down and within line of sight so the shaft does not penetrate something or someone for which it was not intended.
Never shoot if you cannot see the other side of the target!
Where should the fish be speared?
The first question usually asked is, "Where should the fish be speared?" Generally, the best shot is slightly above and forward of the pectoral fin in the gill plate area. Any shot from the eye back to the pectoral fin is usually a good shot, except in the upper area behind the eye. On a large fish, the bone structure in this area is enough to prevent penetration and can break a tip or bend the shaft. If a fish is shot in the soft gut area, it will usually work itself free. The shot placement should be 2 to 3 centimeters (1 to 1 ½ inches) behind the eye or lateral line, depending on how far the fish is away from the hunter.
A technique used for large fish is to spear the fish forward of the caudal (tail) fin to limit its swimming ability.
A technique used for large fish is to spear the fish forward of the caudal (tail) fin to limit its swimming ability.
Approach

The use of scuba is another important factor. As a rule, the noise of your bubbles will chase fish away, so patience must be especially applied. Pelagic (open ocean) fish are far more difficult to take when using scuba.
When approaching a free-swimming fish, keep your body profile in a non-threatening position. Approach from below or even with the fish, not from above, except for bottom fish such as halibut or sole. In stalking a fish, try to be fluid and smooth with motions. Avoid rapid, jerky movements.
When approaching a free-swimming fish, keep your body profile in a non-threatening position. Approach from below or even with the fish, not from above, except for bottom fish such as halibut or sole. In stalking a fish, try to be fluid and smooth with motions. Avoid rapid, jerky movements.
Aiming
Aiming a speargun is just like firing a land weapon. The arm that holds the gun should be fully extended so the hunter can sight down the barrel. The other hand is usually placed on the butt of the gun to hold it securely. In this position, the gun becomes an extension of the arm; the trigger should be squeezed, not pulled or jerked. Each underwater hunter will have personal adaptations to this format, but success depends upon a rigid, extended gun with a smooth firing motion and a direct line of sight.
Stalking Prey

Patience is a major part of successful spearfishing, but some techniques do exist to attract fish to you. One method, which is most popular for attracting bottom fish, is to chum for them by either bringing bait into the water or breaking up edible materials found in the area, but this is not recommended as it may attract other species that are not wanted.
Another method used to attract pelagic fish is stroking the gunstock to make a distinctive audio signature or strumming the bands. Slapping fins on the surface will also attract attention. Another common method is to learn where the fish routinely travel. Finding the most often utilized routes of travel for the prey sought is a concept that will result in far more successful underwater hunts.
In areas of heavy underwater vegetation, such as kelp forests, a common technique is to hide in the middle of the surface canopy, be as still as possible, and let the natural curiosity of the fish bring them in. Divers around oil rigs will often try to come up under the fish or hide in the middle of the rig and shoot outward away from the rig toward the target. The diver in a reef area will hide where there is a clear shot between the reefs.
Another method used to attract pelagic fish is stroking the gunstock to make a distinctive audio signature or strumming the bands. Slapping fins on the surface will also attract attention. Another common method is to learn where the fish routinely travel. Finding the most often utilized routes of travel for the prey sought is a concept that will result in far more successful underwater hunts.
In areas of heavy underwater vegetation, such as kelp forests, a common technique is to hide in the middle of the surface canopy, be as still as possible, and let the natural curiosity of the fish bring them in. Divers around oil rigs will often try to come up under the fish or hide in the middle of the rig and shoot outward away from the rig toward the target. The diver in a reef area will hide where there is a clear shot between the reefs.
Techniques
The more advanced diver will adapt the speargun for a variety of specialized needs. The most common is the addition of a line reel to enable playing a large fish as the pole fisherman does. Many spearfishers place a small light on the barrel to sight the gun at night or for searching through large crevices in a reef structure.
Often, guns are rigged with stainless steel cable for use in rocky crevices, around wrecks and especially near oil rigs to prevent a speared fish from fraying the shock line and breaking free.
Rubber slings tend to lose 25 percent of their power in about 10 minutes when cocked, so many spearfishers with multi-band guns will leave one sling uncocked and periodically rotate cocked slings.
When using a pole spear, the diver can simply pull the band back and let the spear fire. A better technique that can be employed with pole spears is to twist the band around the shaft when pulling tension. When the shaft is released, it spins and increases accuracy. This is similar to a bullet coming out of a rifle or a football being thrown with a spiral.
Some spearfishers use a technique called "free shafting" in which the shaft is completely detached from the gun after firing, that is, no shock line. A kill or “stoning shot” is almost essential; however, if the fish is not dispatched immediately, it will generally "hole-up" for easy retrieval by the spearfisher. Once a fish has been speared, it should not be removed from your shaft until it has been placed on a stringer, placed in a surface float, or returned to your boat.
Often, guns are rigged with stainless steel cable for use in rocky crevices, around wrecks and especially near oil rigs to prevent a speared fish from fraying the shock line and breaking free.
Rubber slings tend to lose 25 percent of their power in about 10 minutes when cocked, so many spearfishers with multi-band guns will leave one sling uncocked and periodically rotate cocked slings.
When using a pole spear, the diver can simply pull the band back and let the spear fire. A better technique that can be employed with pole spears is to twist the band around the shaft when pulling tension. When the shaft is released, it spins and increases accuracy. This is similar to a bullet coming out of a rifle or a football being thrown with a spiral.
Some spearfishers use a technique called "free shafting" in which the shaft is completely detached from the gun after firing, that is, no shock line. A kill or “stoning shot” is almost essential; however, if the fish is not dispatched immediately, it will generally "hole-up" for easy retrieval by the spearfisher. Once a fish has been speared, it should not be removed from your shaft until it has been placed on a stringer, placed in a surface float, or returned to your boat.
Stringing

When stringing your bounty, choosing the correct stringer is important. There are several types of stringers. A “hoop stringer” is a common type. It resembles a giant safety pin, and the fish is either strung through the eyes or through the mouth and gill opening. The hoop is then closed. A “speed stringer” is another common style. One end has a needle that feeds the stringer through the gill and out the mouth. The line often has a “flopper”, similar to a hinged tab, on it so the fish cannot detach from the line.