Blue Water Hunting and Freediving - Digital Version 1 - Page 83
Capture guide detail .
Continuous capture guide detail at muzzle . to the barrel is a notched grip near the front of the gun . You can carry the gun by holding it here when in transit , fighting a current , or swimming over barren ground .
The gun handle should be positioned at least 13 inches ( 33 centimeters ) from the rear of the gun . Eighteen inches ( 46 centimeters ) is better for aiming , but this distance brings the rear of the gun closer to your face , and gun recoil can produce broken masks , bent noses , fat lips and other serious injury . With a 56-inch ( 1.42-meter ) barrel and a 72-inch ( 1.82-meter ) shaft , the spear tip will be about 18 inches beyond the muzzle , providing good tip visibility . This geometry is excellent for maneuvering and aiming because most divers sight by superimposing their spear tip onto the target .
Eighteen pounds ( eight kilos ) is a good weight for the assembled gun , including the spear and spearhead . This weight reduces both horizontal and vertical gun recoil . ( See the section on accuracy .) The front two-thirds of the gun should be streamlined so that you can move the gun easily through the water . In the water , the gun should be balanced at the handle with a slight tendency to sink at the spear tip end , and it should float after the spear is discharged . You can modify the weight and balance of your gun by attaching weighted , streamlined wooden blocks to the rear third . Adjust the weight of these blocks by drilling holes in them and inserting enough
lead to achieve neutral buoyancy and balance . Generally , you need to add flotation ahead of the handle and weight behind it .
The spear release mechanism is the heart of the gun . It should be at least a two-stage device . One lever , activated by the trigger , releases the second lever , which in turn releases the shaft . Do not experiment here ; select a gun with a reliable , tested spear release mechanism . This mechanism must have an effective safety that positively engages the primary lever ( the lever actuated by the trigger push-rod ). Safeties that engage the trigger are not reliable and may allow accidental release . Test the safety by loading the gun in the water , placing it on safety and pulling the trigger . Afterward , be careful when you release the safety because sometimes faulty safety mechanisms release the spear when they are disengaged . A trigger guard is necessary to prevent accidental discharge caused by an unintentional blow to the trigger . The spear line release mechanism should be timed to release the line just before the shaft is fired . A delayed line release will pull the shaft off its course or break the line .
A push-rod is required to transmit finger pressure backward to the mechanism . Select a gun using lightweight push-rod material to reduce the possibility of accidental discharge if you bump or drop the gun . Make sure the push-rod is strong enough to resist the spear ’ s pressure to release . A weak push-rod will bend and then affect the