I have 2 different ones I have not used them for fishing , i use them for hockey. This one goes behind the glass right behind one of the nets during hockey games. Its a Vivitar ... 785 or 787 both HD
http://www.vivitar.com/products
There are 2 models, mine is the older one. $59 at staples. Its awesome for what i use it for. The Go Pro is awesome also , just lots more money than i wanted to spend. I would try this one first, The better model. Keep in mind battery life if you fish for more than a few hours, as well as recording length.
I originally bought it with the intent of trying it for 2 weeks and returning it if it did not work out and getting the go pro. --- 2 years later i still have it and its awesome.
I also have a bullet cam , Its an older one by Contour, It is the size of a 10 gauge shotgun shell. The key to this was small as possible and as rugged as possible. It has been hit several timesby pucks and still works. I wear it on my ice hockey goalie and forward helmets as well as my motocross helmets. It so far has been indestructible. I liked it for its small size and solid metal construction. It took longer to set up and get the angles down as it does not have a viewer screen, after 3 or 4 times using it , i got it adjusted and mounted with the view i wanted. This is probably not what you want for fishing.
In my opinion you cannot go wrong spending the $$$ on a go pro. If you are willing to spend the $$$.
http://www.chopmtb.com/2013/03/14/whats-the-best-helmet-cam-find-out-in-the-ultimate-pov-action-camera-video-shootout/