This is what I have been using for something telescopic with my goPro and it works great.
The painters pole is this one :
http://www.homedepot.ca/product/easy...on-pole/959739
The extension piece I found at Rona, I can't seem to find it on the site though. And then I drilled a hole through a PVC cap and then epoxied the screw in and then just attached the tripod mount.
This is fairly cheap and is heavy duty and works great for under water shots.