Stephen - Get it for sure mate... cannot recommend them highly enough... but to do it justice you need to take the time out to edit the footage, otherwise you end up never viewing or seeing it again... editing is an art , and when done well, makes for incredible viewing....
GoPro's are insanely good value, and the new ones are even better than the first, they are mind blowing in fact....
I'd advise getting the Underwater Corrective Lens if you using it for fishing as an extra, and get a pole mount fixture so you can attach it to a boat hook for underwater stuff....