The PowerGrip H2O is a waterproof GoPro extension pole and more. Inside its handle is a powerful rechargeable battery that can be used to keep your GoPro powered up, even underwater. Polar Pro has also designed several accessories to use with it to make it more useful than just a selfie stick with a battery.
The PowerGrip H2O by itself is available for $69 through its fully funded Kickstarter or kitted out with accessories for $149. That converts to about AU$100 and AU$210 or £45 and £100. When that pricing ends you'll be able to get it starting at $99 (about AU$140, £65) in November.