Speargun Rubber FAQ

1. What is speargun rubber?
A number of speargun designs use the force of rubber put under tension in order to power a shaft through the water towards a target.  This is achieved by stretching a length of pliable rubber along the speargun barrel to the trigger notch.  A shaft with a suitable spearhead tip is then placed in the barrel.  When the operator presses the trigger the rubber is released and the force that is generated as it snaps back into shape is transferred to the shaft, propelling it from the barrel at a significant speed.  Spearguns are simple but very effective weapons that can be used to hunt a wide range of fish from small reef varieties through to large pelagic species.

2. Should I choose rubber or pneumatic spearguns?
One of the main advantages of rubber spearguns is that they are easy to use, lightweight and affordable.  Rubber spearguns are also low maintenance and the rubbers and other parts are easy to replace. This is ideal for beginners and hobby spearfishermen.   Pneumatic spearguns are more difficult to use and require a lot of maintenance so are more suitable for experienced spearfishermen.  One of the main advantages of the pneumatic design is that it fires much more quietly than rubber based spearguns and this is an important consideration for commercial fishermen. Small pheumatic speaguns can be useful for spearing crays, but be sure to check the legality of this in the area you are intending to dive.

3.  What rubbers do I need for my speargun?
The rubbers (also known as power bands) on your speargun will play a vital role in the power, range and accuracy of your weapon.  You do need to make sure you are using the right rubbers for your speargun model to ensure that your weapon is effective.  The first thing you will need to do is check the manufacturer’s instructions.  Your speargun model will have been rigorously tested for optimum performance so there should be some clear guidance on what rubbers to use in the instruction manual.  You do need to use rubbers created specifically for spearguns.  This will provide you with the high tensile strength and elasticity you need for maximum power upon release.  Rubbers designed specifically for speargun use will also be treated to ensure they are as resistant as possible to saltwater and UV light.  This will ensure that they last for as long as possible.

4. What types of speargun rubbers are available?
You will need to get the right length rubbers for your speargun so it is important to measure the barrel or refer to the manufacturer’s instructions.  You can buy bulk speargun rubber which you can cut to the required length or you can buy pre-cut lengths which are made for most leading speargun brands. This includes the Adrenaline Premade Speargun Powerband which can be used with Rabitech spearguns.

5.  How exactly do speargun rubbers work?
Rubber has a high tensile strength and incredible elasticity.  This means it can be stretched many times its original length before it breaks.  The elasticity means that it can return to its original shape after being stretched.  The combination of high tensile strength and elasticity means that when the rubber returns to its original shape it snaps back with a high energy force.  The further you stretch the rubber the more power is created when the rubber is released.  A speargun is designed to harvest the power created from the release of stretched rubber and transfer it to the waiting spear shaft.  The energy is converted into forward motion which fires the shaft through the water. This is a basic application of dynamics and is incredibly effective underwater.

6.  How long do speargun rubbers last for?
Speargun rubber is designed to be resistant to water and UV light but it will start to degrade over time and with exposure to the elements.  You should be able to use speargun rubbers quite a few times before they need replaced and you can extend their life by keeping them in a dry, dark place when not in use.  You can also lube the rubbers with some silicone grease to keep them supple.  Before you use your speargun check the rubbers over thoroughly for any sign of damage or wear.  This could be dangerous as the rubbers could break under tension if they are worn or damaged.  This could cause the shaft to release unexpectedly or the rubber could snap when you are trying to load the shaft injuring your fingers.  You can judge when a rubber is getting towards the end of its usefulness when the power in the release starts to decline.

7. What length speargun rubbers do I need?
The length and diameter of the speargun rubbers can affect the overall power.  If you have a 90cm speargun then a rubber measuring 50cm with a 16mm diameter will provide you with a standard, medium strength power ideal for reef and wreck fishing.  If you are hunting for larger fish then you can decrease the length of the rubber to 45cm.  This will mean that the rubber has to be put under more tension to stretch it along the length of the barrel and this will increase the power of the shot.  This can result in additional penetration power for the spearhead for larger fish species.

8.  How do you fit rubbers?
The technique of fitting your rubbers will depend on the type of speargun you use.  In general though you fit the rubbers first before the spear shaft, you attach the rubbers to the front opening and then pull them back one at a time and fasten them to the notch at the rear of the barrel.  Both rubbers need to be the same length to ensure a smooth release, however you may choose to have different thickness in rubbers on your gun.

9.  How do I care for speargun rubber?
As with any rubber product you need to store speargun power bands away from direct sunlight and extremes of heat.  Store in a dry, dark place and spray with silicone lube before putting them away to keep them supple.

10. Can I make my own speargun rubbers?
You can buy lengths of speargun rubbers that you can then use to cut and fit your own power bands.  This is suitable for experienced spearfishermen who have time to spend measuring and cutting their rubbers.  However if you are a beginner you will be much better off buying pre-cut rubbers designed specifically for your speargun.  This ensures you have the right length rubbers for your gun and that they are made from the most effective materials.