GoPro Hero 3+ silver or 4 silver?

I am in between which model GoPro to purchase. From what I have seen the 4 silver obviously has some better specs than the 3+ silver. I intend to use it for primarily fishing and such so I am not sure if I would be wasting my money on the 4 if I am not going to utilize all the extra specs. How noticeably different is the video, sound, and picture quality between the two silver models? Never owned or operated a GoPro so that's why I am trying to get some extra insight.

Thanks

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