I have a gopro silver edition. have made a few vids
IMHO you (I) don't need/top of the range. I find my battery lasts a full day with plenty of on time.

most of the aftermarket stuff on ebay works fine I bought extra case floaty doors, stuff to screw it onto the overhead rod holders on my boat etc. never had a water leak out of the afternmarket cheap stuff.

my daughter uses it on her helmet for eventing....horses etc it gets a bit of a hammering.

spent time at the monties not too long ago and just charged each night.

https://www.youtube.com/watch?v=VAmXSC0SSFQ

 I have had the gopro 2 and now the 4 and i bought the 4 before doing euro trip and it was the best thing i did. The image quality is great, i find my battery lasts a long time, I have also bought after market stuff from ebay and the only problem i could give is that 1 of the aftermarket batteries didn't hold charge for long and is gone now but you get what you pay for. I find mine will use alot of battery when using the wifi with an Iphone and the software is fine but there are so many editting programs out there if doesn't really matter. I have used both fishing and diving and can't fault them really, between the gopro and my phone there really is no reason for me to buy a digital camera anymore. Hope this helps.

 Go pro 4 silver.

 I love my GoPro 4 black. I get a stack of accessories for under $30 of eBay and they are excellent as well. I got a couple of spare batteries which don't last nearly as long but we're very cheap so I'm happy there too as they are really just a get out of jail item while the main battery is getting recharged. I still get a good run out of the generic battery.

A couple of things to be aware of. The iPhone can't process the imagery well or even at all when using the GoPro on some higher settings like frame speed or ultra high definition. It's great on full HD and 30 frames per second but you can go to a stunning 120 frames per second on full HD. The phone cant process this so you'll have to rely on your pointing skills to get the right shot. Same again with the ultra HD settings.

You also need to make sure you get a good micro SD card. A Sandisk Extreme plus is what I got as I wasn't confident the Extreme would be fast enough for the higher settings.

The big one is with the above is that a lot of computers can't handle it either. I need to upgrade mine. You need the latest generation core I7 processor with lots of RAM plus a very good graphics card. The GoPro website lists the details.

so basically this shows just how good the GoPro is and is worth the money. There's online video comparisons of the GoPro vs other generic type action cameras to show the difference. Some of those other ones are actually pretty good though and I'm considering getting one as well to allow two cameras. One mounted on a gaff for underwater action while the other is above the water line taking footage at the same time.

 Plenty of comments on battery life saying "get a good run" but how long are we talking ?  original batteries vs the cheapies ?

Get the 4 sliver (I have 2) - the screen comes in very handy setting up shots etc.

If your not in a huge rush you can get them for around $400
(mine were $375 and $399 and just got one for a mate at $392) keep an eye on Ebay group deals or Ebay deals - they come up every now and then - I wouldn't pay anything above $450 - yes that's from local stores with full warranty (Dickysmiths and Goodguys)

Battery life varies but I have the screen turn off after a few minutes (generally just use it to set up a shot off the launcher etc) and don't use wifi they both use extra battery. I get around 90min doing this (at a guess).

Yes only use the high rated cards (as per gopro site) or you may have issues and find you missed footage (again can get these at around half price of ebay

Thanks for all that advice guys, much appreciated. 4 silver is looking the best option so will keep a look out for the bargains. will definitely set up to maximize battery based on all the above advice. Cheers

 Is pretty much the old Hero 3 Black, which was the previuos top of the range. Offers pretty good value. I still use the 3 Black, always been happy with it after the original was replaced under warranty. ithad that bad software issue which plagued the original Black 3'3. No issues since. I only shoot as 920 or 1080, find my Andoid phone has no problems giving me remote image, with some lag, and my i5 Surface Pro 3 with 8Gb of Ram handles the processing fine. The older Celeron lappie would spit the dummy over a certain length of clip, and was very slow when processing/previewing.

 Do yourself a favor and check out the new garmin virb xe, brilliant peice of equipment! Im selling my gopros to get another!!

 I use a 3+ silver and have had no problems with it at all. You can get a battery extension that clips onto the back of the existing camera if you want to get extra battery life out of it but I find with out it you will get about 3 hrs of non stop recording (I have both options). I have made a few vids that you can check out on https://www.youtube.com/channel/UCHzN0YOYF8JkXWBXqmPQkXw and then see what you reckon. the gopro editing software is pretty user friendly as well.

Cheers again guys. Picked up the 4 silver and ready to take out there once the wind buggers off. Can't wait for demersal action!

Last question is does anyone have issues with the fact the file sizes are huge? Its quite possible its just the one person I know with one but they seem to struggle to fit even a 30 min clip onto a large hard drive. The person isn't very computer savy so not sure if its him or the files are just really big.

 17 minutes is 3.72 gig according to a clip I took at 1080

What does he term a large hard drive?? shouldn't be an issue with any half decent comp hard drive

Also may be that he is shooting with protune turned on
I leave it off - don't really need it.

there is a new gopro model out with an rrp of $150
it seems to lack the lcd screen, but very good value