If you can pick up a GoPro 4 Silver for a good price, then it comes highly recommended, as it can record stunning video in 4k quality, and produce some superb 12mp photographs.
Obviously a larger Digital SLR will beat it for over all picture quality, but imagine trying to keep one of those totally dry in heavy rain.
The GoPro protective case, is totally waterproof down to a depth of 30ft, and you will never miss a photo opportunity if the weather is poor.
If you want the ability to record a video in 4k quality for a continuous 4hrs non stop, then Smatree make a lithium battery pack for around £20.
As long as your micro SD card has sufficient capacity and speed to record in 4k, then nothing will stop you producing very lengthy videos.