In general a longer shaft will give you a greater range. You need to consider what length speargun and shaft you want to use when you are in the water. The longer options will provide you with greater range and this means you do not have to get so close to your target. However longer spearguns and shafts can be difficult to manoeuvre underwater and will take some getting used to. If you are just starting out with spearfishing it is best to stick to shorter options which are easier to use and aim at close range targets.
A smaller diameter shaft has a lower mass compared to a thicker shaft of the same length. This means it will travel faster over shorter distances. This is useful if you are hunting fast moving smaller sized fish at close range in reef environments. Also smaller diameters shafts will have less momentum behind them and this means if they hit rocks the tip is less likely to get damaged. This is a good option for beginners who will most likely miss more than they hit at first. However if you are targeting larger fish then penetration power becomes more important than initial firing speed. Thicker diameter shafts are heavier and will travel with more momentum through the water and strike the target much harder.
If you have a threaded-end shaft then you will need spearhead options that can be screwed into place. This includes screw-on fixed-tip and screw-on slip-tip heads. The fixed-top option is ideal for hunting in wrecks and reefs as the tip can be replaced (and not the whole shaft) if it gets damaged from hitting rocks and other underwater debris. Slip-tip heads are much more suitable for striking larger fish as they offer much better holding power.
You do need to attach a float line to your shaft if you are going to be targeting larger fish. Floats will help to slow down and subdue larger fish. Try to avoid attaching the float line to your gun as this can damage the gun when the fish starts to thrash and you could drop the gun and lose it. The best set up for large game fish is a bungie style float-line linked to a medium size float. You can then attached this to the shaft so that when it strikes the target the float will create drag and help to subdue the fish.
Big game fish are powerful and fast and you will need a heavy duty spear tip that will penetrate into at least two feet of flesh. This will ensure that the shaft holds true and does not simply tear free when the fish starts to thrash. In order to hold a heavy duty spear tip you need a solid, durable spear shaft such as those made from aluminium.
Spearguns are not designed for use out of the water and fatalities have occurred from loading, unloading, or using spearguns in such situations. Adreno does not recommend any speargun to be used in this way. Additionally, you should note that it is not usually possible to accurately aim at objects in the water when you are on the surface.
The best places for spear shafts are in areas that are well populated with a variety of fish species. Shorelines, wrecks and reefs provide ideal habitats for marine life with plenty of food and shelter. This should mean that you do not have to travel too far before you find good hunting grounds. If you want to hunt for big game fish then you will need to move out to open waters and an experienced boat crew will be able to take you out to prime hunting spots.
It will depend on where you are hunting as to what sort of fish you could catch. Popular fish for spearfishing in waters around New Zealand include yellow tail kingfish. In Florida groupers are a key target and in the Great Barrier Reef tuna are abundant and a prime catch for spearfishermen.
After each spear fishing session rinse your equipment including your spear shafts in fresh cool water and then leave to dry. Check over aluminium and stainless steel shafts for any signs of damage or corrosion. You may need to replace the spearhead or shaft if it has been damaged or is worn. Once you have done this you can then store your shafts in a cool, dark place until you need them again. It is a good idea to keep all of your spearfishing equipment together in one place so that you can find it quickly and easily when you need it next.